Automatic playing piano, automatic playing method, and automatic playing program

Abstract

To provide an automatic piano that can reduce adjustment time without degrading quality of played sound.SOLUTION: An automatic piano 100 that executes a performance by driving keys 1 based on performance information MP comprises: a setting section 11 that sets adjustment time AT for adjusting sounding timing lag due to the movement delay time from reception of a performance instruction for one note specified in the performance information MP to sounding of the one note; and a conversion section 12 that converts intensity of each note specified in the performance information MP according to the adjustment time AT set by the setting section 11.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a piano equipped with an automatic performance function.

Background Art

[0002] For example, as disclosed in Patent Document 1 below, there is an automatic performance piano that performs a performance by driving keys based on performance information. In an automatic performance piano, a solenoid is driven based on performance information, thereby performing a key pressing operation. Then, the hammer performs a string hitting operation by the key pressing operation, and a performance sound is emitted.

[0003] Also, a system for performing a session performance using two automatically-played pianos connected by a network and located in remote locations is disclosed in Patent Document 2 below.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described above, in an automatic performance piano, since a performance sound is emitted after mechanical operations after inputting performance information, an operation delay time occurs. Therefore, in an automatic performance piano, an adjustment time for adjusting the operation delay time from receiving a performance instruction based on performance information to sounding is set. Users of an automatic performance system have a desire to shorten this adjustment time. For example, in a system that uses an automatically-played piano at a remote location connected by a network, it is expected to further improve the utility value of the automatically-played piano by shortening the adjustment time.

[0006] In the aforementioned Patent Document 1, a table is created for each instrument that associates the intensity (velocity) specified by the performance information (MIDI) with the drive instruction value of the solenoid. However, Patent Document 1 does not meet the recent demand for shorter adjustment times.

[0007] The objective of this invention is to provide an automatic playing piano that can shorten adjustment time without degrading the quality of the sound produced. [Means for solving the problem]

[0008] An automatic playing piano according to one aspect of the present invention is an automatic playing piano that performs a performance by driving keys based on performance information, and comprises a setting unit that sets an adjustment time to adjust for the timing difference in sound production due to the operation delay time from receiving a performance instruction for a note specified in the performance information until the note is actually played, and a conversion unit 12 that converts the intensity of each note specified in the performance information according to the adjustment time set by the setting unit.

[0009] An automatic performance method according to another aspect of the present invention is an automatic performance method that performs a performance by driving keys based on performance information, and includes setting an adjustment time to adjust for the timing difference in sound production due to the operation delay time from receiving a performance instruction for a note specified in the performance information until the note is sounded, and converting the intensity of each note specified in the performance information according to the set adjustment time.

[0010] Furthermore, this invention is also directed towards automatic performance programs. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide an automatic playing piano that can shorten adjustment time without degrading the quality of the sound produced. [Brief explanation of the drawing]

[0012] [Figure 1] This is a diagram showing the configuration of an automatic playing piano according to an embodiment. [Figure 2] This is a system block diagram of an automatic playing piano. [Figure 3] This is a diagram showing the data format of performance information. [Figure 4] This figure shows an example of an intensity-operation delay time table. [Figure 5] This figure shows an example of an intensity conversion table. [Figure 6] This is a functional block diagram of the controllers included in an automatic playing piano. [Figure 7] This figure shows the relationship between input intensity and output intensity, and the relationship between input intensity and excess delay time, when no intensity conversion is performed. [Figure 8] This figure shows the relationship between input intensity and output intensity, and the relationship between input intensity and excess delay time, after intensity conversion. [Figure 9] This is a flowchart showing the automatic performance method according to the embodiment. [Figure 10] This figure shows another embodiment of the relationship between input intensity and output intensity when intensity conversion is performed, and the relationship between input intensity and excess delay time. [Modes for carrying out the invention]

[0013] The following describes an embodiment of the present invention: an automatic playing piano, an automatic playing method, and an automatic playing program, with reference to the attached drawings.

[0014] {1. Overall structure of automatic performance} Figure 1 is a diagram showing the configuration of the automatic playing piano 100 according to this embodiment. Figure 1 shows a side view (partial cross-sectional view) of the mechanical sound-producing mechanism (sound-producing mechanism corresponding to one key) of the automatic playing piano 100. In the following description, the right side of Figure 1 will be referred to as the front side of the automatic playing piano 100, and the left side of Figure 1 will be referred to as the rear side of the automatic playing piano 100.

[0015] As shown in FIG. 1, the automatic playing piano 100 includes keys 1, an action mechanism 3 that transmits the movement of the keys 1 to hammers 2, strings 4 that are struck by the striking movement of the hammers 2, solenoids 5 for driving the keys 1, and dampers 6 for stopping the vibration of the strings 4. These components are provided corresponding to each of a plurality of keys (e.g., 88 keys) of the piano.

[0016] The automatic playing piano 100 has an automatic playing function by driving the solenoids 5, and like a normal acoustic piano, it can be played by a player pressing the keys 1. The mechanical operations during non-key-pressing and key-pressing described below are the same during automatic playing and playing by a player. When not pressing the key 1, it is in the rest position (position with a stroke amount of 0 mm) shown by the solid line in FIG. 1. The key 1 is pushed down from the rest position to the end position in response to a key-pressing operation (operation of pushing down the right side of the key 1 in FIG. 1). In FIG. 1, the end position of the key 1 is shown by a two-dot chain line. When the key 1 is pressed down, due to the operation of the action mechanism 3, the hammer 2 rotates to the string-striking position 2E (position shown by a dotted line in FIG. 1), and the damper 6 moves upward from the string 4 to release the string 4. By striking the released string 4 with the hammer 2, a musical tone corresponding to the key 1 subjected to the key-pressing operation is produced. Note that the back check 7 is a member for preventing the hammer 2 from running wild due to the recoil during string-striking.

[0017] Next, the operations peculiar to automatic playing will be described. The solenoid 5 is provided at the lower part of the rear end of the corresponding key 1 and is driven based on a control signal supplied from the controller 10. In response to the driving of the solenoid 5, the plunger part protrudes in the axial direction (upward direction), thereby pushing up the rear end part of the corresponding key 1. By the pushing-up operation by the plunger, the key 1 is subjected to a key-pressing operation. As a result, string-striking by the hammer 2 is performed by the same operation as described above. In the example of FIG. 1, the solenoid 5 is provided with a speed sensor for detecting the operating speed of the plunger, and the output of the sensor is fed back as a feedback signal to the controller 10.

[0018] {2. Configuration of the System} Figure 2 is a block diagram showing the configuration of the computer system, including the controller 10, of the automatic playing piano 100 shown in Figure 1. As shown in Figure 2, the automatic playing piano 100 includes a CPU 20, ROM 21, RAM 22, storage device 23, control unit 24, sound source unit 25, and sound system 26. These devices are connected via a system bus 29. A solenoid 5 is also connected to the system bus 29 via a PWM generator (not shown).

[0019] The CPU 20 controls the overall operation of the automatic playing piano 100. ROM 21 stores control programs executed by the CPU 20 and various data. RAM 22 is used as the CPU 20's work area. Storage device 23 stores the keyboard control program P1, performance information MP, intensity-operation delay time table T1, intensity conversion table T2, adjustment time AT, and allowable delay time PDT. Storage device 23 can be configured with various storage media, such as a hard disk or semiconductor memory. The keyboard control program P1 performs processes such as setting the adjustment time AT to adjust timing discrepancies in the automatic playing function, and converting the intensity of each note specified in the performance information MP according to the adjustment time AT. The contents of each data MP, T1, T2, AT, and PDT will be described later.

[0020] The control unit 24 is an interface for the user to perform various operations related to automatic playback (start, stop, song selection, etc.). The sound source unit 25 and sound system 26 are functional units for directly reproducing performance information MP without relying on the vibration of the strings 4. The control signal for driving the solenoid, generated in the CPU 20, is converted into a PWM signal via a PWM generator (not shown) and supplied to the solenoid 5. The amount of drive of the solenoid 5 is controlled according to the pulse width of the supplied PWM signal.

[0021] {3. Adjustment time AT and allowable delay time PDT} During automatic playback, the CPU 20 supplies a control signal to the solenoid 5 based on the performance information MP. When the solenoid 5 is driven in response to the control signal, key 1 is pressed, the action mechanism 3 operates, and the hammer 2 strikes string 4. This produces a musical sound based on the performance information MP. Thus, in the automatic playing piano 100, there is an operational delay time due to the operation of various mechanisms between the time the automatic playing piano 100 receives a performance instruction based on the performance information MP from the CPU 20 and the time it actually produces a sound. This operational delay time differs depending on the intensity (velocity) of each note specified in the performance information MP. In order to produce a sound with high intensity, the hammer 2 needs to strike string 4 strongly, so the solenoid 5 is given a control signal to operate it quickly. Conversely, in order to produce a sound with low intensity, the solenoid 5 is given a control signal to operate it slowly. Therefore, the operational delay time for low-intensity sounds is longer than that for high-intensity sounds.

[0022] Therefore, an adjustment time AT is set to adjust for any timing discrepancies in sound production during automatic playback. For example, if the adjustment time AT is 0.5s, the CPU 20 adjusts the timing of the control signal supply so that the sound is produced 0.5s after inputting the data for each sound recorded in the performance information MP. Alternatively, when receiving the performance information MP via a network, the CPU 20 adjusts the timing of the control signal supply so that the sound is produced 0.5s after receiving the data for each sound recorded in the performance information MP. In other words, the timing of sound production is adjusted by supplying the control signal to the solenoid 5 earlier for weaker sounds and later for stronger sounds. The adjustment time AT is set by the user and stored in the storage device 23.

[0023] Recently, there has been a user need to shorten the adjustment time AT. Therefore, the keyboard control program P1 of this embodiment shortens the adjustment time AT by performing a conversion that increases the intensity of weak sounds. In the automatic playing piano 100 of this embodiment, an allowable delay time PDT is also set. The allowable delay time PDT is the time during which sound production is permitted beyond the adjustment time AT. The keyboard control program P1 performs a conversion that increases the intensity of weak sounds so that they fit within the allowable delay time PDT, which is slightly later than the adjustment time AT. This avoids the need to increase the amount of conversion for very weak sounds in order to maintain the adjustment time AT. In other words, it is possible to shorten the adjustment time AT while avoiding a decrease in the quality of the played sound for weak sounds.

[0024] {4. Table} Figure 3 shows the data format of the performance information MP. In this embodiment, SMF format data is used as the performance information MP. The performance information MP records time information, intensity (velocity), and key number. The key number is information for identifying the key 1 to be played, and is a unique number assigned to each of the keys 1 (e.g., 88 keys) of the automatic playing piano 100. The intensity is information corresponding to the speed of the hammer 2 that realizes the string striking action, and indicates the volume of the musical note to be produced. These key numbers and intensity are recorded in the performance information MP, corresponding to each piece of time information.

[0025] Figure 4 shows an example of the intensity-operation delay time table T1. The intensity-operation delay time table T1 records the correspondence between intensity (velocity) and operation delay time. As mentioned above, the operation delay time from receiving a performance instruction based on the performance information MP from the CPU 20 until actually playing a sound differs depending on the intensity of the sound recorded in the performance information MP. The intensity-operation delay time table T1 records the operation delay time corresponding to all intensities. In the example in Figure 4, operation delay times t1 to t127 are recorded for the lowest intensity 1 to the highest intensity 127.

[0026] Figure 5 shows an example of the intensity conversion table T2. The intensity conversion table T2 is a table that converts the intensity specified in the performance information MP. The keyboard control program P1 shortens the adjustment time AT by performing a conversion that increases the intensity of weaker sounds based on the intensity conversion table T2. In the example in Figure 5, the corresponding output intensities are recorded for input intensities from the lowest intensity 1 to the highest intensity 127. For example, in the example in Figure 5, it is shown that the input intensity of the lowest intensity 1 is increased to intensity 23. The method for generating the intensity conversion table T2 will be described later.

[0027] {5. Controller Configuration} Figure 6 is a functional block diagram showing the configuration of the controller 10. As shown in Figure 6, the controller 10 comprises a setting unit 11, a conversion unit 12, a keyboard control unit 13, and a measurement unit 14. These setting unit 11, conversion unit 12, keyboard control unit 13, and measurement unit 14 are functional units realized by the keyboard control program P1 being executed on the CPU 20 while using RAM 22 as a work area. In other words, the setting unit 11, conversion unit 12, keyboard control unit 13, and measurement unit 14 are functional units provided by the CPU 20.

[0028] The setting unit 11 saves the adjustment time AT and the allowable delay time PDT to the storage device 23. The setting unit 11 records the adjustment time AT and the allowable delay time PDT based on the setting operation performed by the user using the operation unit 24. The conversion unit 12 converts the intensity of each sound recorded in the performance information MD based on the intensity conversion table T2. The keyboard control unit 13 supplies control signals to the solenoid 5 while adjusting the sound generation timing based on the converted performance information MD received from the conversion unit 12 and the intensity-operation delay time table T1.

[0029] The measurement unit 14 performs a measurement process to generate an intensity-operation delay time table T1. The measurement unit 14 generates the intensity-operation delay time table T1 by measuring the time from when the CPU 20 gives a performance instruction for one note included in the performance information MD until the hammer 2 operates and that note is actually produced. With the conversion process in the conversion unit 12 turned OFF, the measurement unit 14 measures the operation delay time until sound is produced for all intensities. For example, the measurement process by the measurement unit 14 is performed before the product leaves the factory. Alternatively, the user may perform the measurement process at any time. The measurement unit 14 stores the generated intensity-operation delay time table T1 in the storage device 23.

[0030] The keyboard control program P1 will be described as being stored in the storage device 23 as an example. In other embodiments, the keyboard control program P1 may be provided stored in a storage medium such as semiconductor memory or DVD. The CPU 20 may access the storage medium via a device interface and save the keyboard control program P1 stored in the storage medium to the storage device 23 or ROM 21. Alternatively, the CPU 20 may access the storage medium via a device interface and execute the keyboard control program P1 stored in the storage medium. Alternatively, the CPU 20 may download the keyboard control program P1 from a server on a network via a communication interface and save the downloaded keyboard control program P1 to the storage device 23 or ROM 21.

[0031] {6. Method for generating the intensity conversion table T2} Next, the method for generating the intensity conversion table T2 will be described. The setting unit 11 generates the intensity conversion table T2 as shown in Figure 5 based on the adjustment time AT and the allowable delay time PDT. Figures 7 and 8 are diagrams illustrating the method for generating the intensity conversion table T2.

[0032] In Figures 7 and 8, the horizontal axis represents the input intensity of the performance information MP, and the left vertical axis represents the output intensity of the performance information MP, i.e., the intensity after conversion by the conversion unit 12. The right vertical axis represents the excess delay time relative to the adjustment time AT. The input and output intensity are set to integer values ​​from a minimum intensity of 1 to a maximum intensity of 127. Figure 7 shows the graph when no conversion is performed by the conversion unit 12. In other words, the input intensity is output as is as the output intensity. In this case, in the example shown in the figure, when the input intensity falls below 40, the operation delay time exceeds the adjustment time AT. That is, for weak sounds with an input intensity from 1 to 40, an excess delay time occurs. Based on this relationship, the setting unit 11 acquires an input intensity of 40 as the sound production delay start intensity.

[0033] Furthermore, the setting unit 11 obtains the allowable weakest intensity based on the allowable delay time PDT. The allowable weakest intensity is the weakest intensity at which the excess delay time falls within the allowable delay time PDT. In the example in Figure 7, for example, if the allowable delay time PDT is 0.05 s, the allowable weakest intensity is around intensity 25. Then, the setting unit 11 generates an intensity conversion table T2 in the form of a graph as shown in Figure 8. The setting unit 11 pushes up the weakest intensity, intensity 1, to the allowable weakest intensity (25 in the example in the figure). Then, it generates the intensity conversion table T2 by linearly interpolating from the sound delay start intensity 40 to the allowable weakest intensity 25. As a result, the curve of the excess delay time after conversion is as shown in Figure 8, and even at the weakest intensity, intensity 1, the excess delay time falls within the allowable delay time PDT (0.05 s in the example in the figure).

[0034] {7. Automatic performance method} Next, the automatic performance method according to this embodiment will be described with reference to the flowchart in Figure 9. The automatic performance method is executed by the keyboard control program P1 running on the CPU 20.

[0035] (Step S1) In step S1, the setting unit 11 sets an adjustment time AT to adjust for the timing discrepancy in sound production due to the operational delay time from receiving the instruction to play a note specified in the performance information MP until the note is actually played. As described above, the adjustment time AT is set by user operation. For example, the user sets a time such as 0.1s or 0.2s as the adjustment time AT. The setting unit 11 also sets an allowable delay time PDT. The allowable delay time PDT is set by user operation. For example, the user sets a time such as 0.1s or 0.05s as the allowable delay time PDT. The setting unit 11 stores the adjustment time AT and the allowable delay time PDT in the storage device 23.

[0036] (Step S2) In step S2, the conversion unit 12 converts the intensity of each sound specified in the performance information MP according to the adjustment time AT set in the setting unit 11. In other words, the conversion unit 12 converts the intensity of each sound specified in the performance information MP based on the intensity conversion table T2. Since the intensity conversion table T2 is generated based on the adjustment time AT and the allowable delay time PDT, sounds with relatively high intensity among the sounds specified in the performance information MP are played in accordance with the adjustment time AT. In contrast, sounds with low intensity among the sounds specified in the performance information MP are played in accordance with the adjustment time AT if no excess delay time occurs. Sounds with excess delay time are played slightly later than the adjustment time AT within the range of the allowable delay time PDT.

[0037] {8. Features and Effects of the Embodiment} As described above, the automatic playing piano 100 according to this embodiment is an automatic playing piano 100 that performs a performance by driving the key 1 based on performance information MP, and includes a setting unit 11 that sets an adjustment time AT to adjust the timing difference of sound production due to the operation delay time from receiving a performance instruction for one note specified in the performance information MP until the sound of the note is produced, and a conversion unit 12 that converts the intensity of each note specified in the performance information MP according to the adjustment time AT set by the setting unit 11.

[0038] The automatic playing piano 100 of this embodiment can convert the intensity of the sound specified in the performance information MP according to the set adjustment time AT. For example, if the adjustment time AT is set to be short, conversions such as boosting the volume of quiet sounds are performed accordingly. According to this embodiment, it is possible to provide an automatic playing piano 100 that can shorten the adjustment time AT without degrading the quality of the performance sound.

[0039] In the automatic playing piano 100 of this embodiment, the conversion unit 12 may convert the intensity of each note so that the intensity of each note is greater than the intensity specified in the performance information MP, for each note whose operating delay time exceeds the adjustment time AT.

[0040] According to this embodiment, even sounds with low intensity can be produced in accordance with the adjustment time AT.

[0041] In the automatic playing piano 100 of this embodiment, the setting unit 11 may set an allowable delay time PDT relative to the adjustment time AT when it is permissible for the operation delay time to exceed the adjustment time AT, and the conversion unit 12 may convert the intensity of each note specified in the performance information MP according to the adjustment time AT and the allowable delay time PDT.

[0042] According to this embodiment, the intensity of the sound specified in the performance information MP can be converted according to the set adjustment time AT and allowable delay time PDT. Since it is permitted to produce sound with a delay relative to the adjustment time AT, excessive conversion is prevented for sounds with low intensity, and the quality of the performance sound can be improved while shortening the adjustment time AT.

[0043] {9. Other Embodiments} In the above embodiment, the adjustment time AT and the allowable delay time PDT are set, but the allowable delay time PDT does not need to be set. In this case, the setting unit 11 generates an intensity conversion table T2 based on the adjustment time AT. This intensity conversion table T2 increases the intensity of weaker sounds, and converts all sounds of varying intensities so that they fit within the adjustment time AT. This also makes it possible to shorten the adjustment time AT.

[0044] In the above embodiment, as shown in Figure 8, the conversion unit 12 boosted the intensity of the quietest sound to the allowable weakest intensity, and converted the intensity of each sound specified in the performance information MP so as to linearly interpolate between the boosted allowable weakest intensity and the sound delay start intensity. In another embodiment, as shown in Figure 10, the conversion unit 12 may boost the intensity of the quietest sound to the allowable weakest intensity, and convert the intensity of each sound specified in the performance information MP so as to linearly interpolate between the boosted allowable weakest intensity and the highest intensity. In the examples shown in Figures 8 and 10, conversion was performed by linear interpolation, but interpolation may also be performed by curve. [Explanation of symbols]

[0045] 1...Key, 2...Hammer, 3...Action mechanism, 4...String, 5...Solenoid, 6...Damper, 10...Controller, 11...Setting unit, 12...Conversion unit, 13...Keyboard control unit, 14...Measurement unit, 23...Storage device, AT...Adjustment time, PDT...Allowable delay time, T1...Intensity-operation delay time table, T2...Intensity conversion table, P1...Keyboard control program

Claims

1. An automatic playing piano that performs music by driving keys based on performance information, A setting unit sets an adjustment time to adjust for the timing discrepancy in sound production caused by the operational delay time from receiving the instruction to play a single note specified in the performance information until the first note is played, A conversion unit that converts the intensity of each sound specified in the performance information according to the adjustment time set in the setting unit, Equipped with, The conversion unit converts the intensity of each note so that the intensity of each note is greater than the intensity specified in the performance information for each note whose operation delay time exceeds the adjustment time, thereby enabling automatic piano performance.

2. The setting unit sets an allowable delay time relative to the adjustment time if it is permissible for the operation delay time to exceed the adjustment time. The automatic playing piano according to claim 1, wherein the conversion unit converts the intensity of each sound specified in the performance information according to the adjustment time and the allowable delay time.

3. The automatic playing piano according to claim 2, wherein the conversion unit converts the intensity of each sound specified in the performance information such that the operation delay time from receiving a performance instruction for the lowest intensity sound to playing the lowest intensity sound does not exceed the allowable delay time.

4. The automatic playing piano according to claim 2, wherein the intensity at which the operation delay time until a sound is produced matches the adjustment time is defined as the sound production delay start intensity, and the intensity at which the operation delay time until a sound is produced matches the allowable delay time is defined as the allowable weakest intensity, the conversion unit pushes up the intensity of the smallest sound to the allowable weakest intensity, and converts the intensity of each sound specified in the performance information so as to linearly interpolate between the pushed-up allowable weakest intensity and the sound production delay start intensity.

5. The automatic playing piano according to claim 2, wherein when the minimum allowable intensity is defined as the intensity at which the operation delay time until the sound is produced coincides with the allowable delay time, the conversion unit pushes up the intensity of the smallest sound to the minimum allowable intensity, and converts the intensity of each sound specified in the performance information so as to linearly interpolate between the pushed-up minimum allowable intensity and the maximum intensity.

6. An automatic performance method that performs music by driving keys based on performance information, This involves setting an adjustment time to correct the timing discrepancy in sound production caused by the operational delay time between receiving the instruction to play a single note specified in the performance information and actually playing the single note, The intensity of each note specified in the performance information is converted according to the set adjustment time, Includes, The above conversion includes converting the intensity of each sound such that, for each sound whose operating delay time exceeds the adjustment time, the intensity of each sound becomes greater than the intensity specified in the performance information.

7. An automatic performance program that causes a computer to execute an automatic performance method, The aforementioned automatic performance method is An automatic performance method that performs music by driving keys based on performance information, This involves setting an adjustment time to correct the timing discrepancy in sound production caused by the operational delay time between receiving the instruction to play a single note specified in the performance information and actually playing the single note, The intensity of each note specified in the performance information is converted according to the set adjustment time, Includes, The conversion includes an automatic performance program that converts the intensity of each sound such that, for each sound whose operating delay time exceeds the adjustment time, the intensity of each sound becomes greater than the intensity specified in the performance information.

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