Legato Note Selection Logic for Electronic Keyboards
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Solution Overview
Problem
Existing electronic musical instruments face challenges in performing desired tone generations, particularly in legato performances, due to mis-coordination between note selection and key operation states, leading to unnatural sound production.
Innovation Solution
An electronic musical instrument with selectors that decide whether to select a note in response to tone generation stopping operations, using a decider to assess pitch differences and performance methods, ensuring accurate note selection matching the performer's intention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If each assigner selects a note according to key depressing operation only, then the note selection is simple and direct, but the tone generation becomes unnatural in legato performance when a key is released immediately after another key is depressed
Solution Approach 1:
The system performs preliminary evaluation of the key-off operation to determine whether it represents a legato performance before actually executing the note reselection. By assessing the timing relationship between the key-on of the first key and the key-off of the second key in advance, the system prepares to maintain natural legato tone generation without waiting for the actual key release to occur
Solution Approach 2:
The system uses feedback from the key operation timing information to dynamically adjust note selection behavior. By monitoring whether a key-off operation occurs within a predetermined time period after a key-on operation, the system feedback-controls whether to reselect notes, thereby adapting to legato performance patterns and maintaining natural sound transitions
2Speed
If the system reselects notes after every key-off operation, then the tone generation responds quickly to key releases, but it produces unnatural sounds in legato performance where keys are released in rapid succession
Solution Approach 1:
The system performs preliminary assessment of the key-off operation timing relative to the subsequent key-on operation before executing note reselection. This advance evaluation prevents premature or inappropriate reselection that would disrupt legato flow, while still maintaining rapid response when appropriate
Solution Approach 2:
The system dynamically adjusts its note selection behavior based on the detected performance pattern. When legato performance is detected (key-off within predetermined time of key-on), the system suppresses automatic reselection to maintain smooth transitions. When non-legato performance is detected, the system allows normal reselection for clear articulation
3Reliability
If the system suppresses note reselection during legato performance, then natural tone transitions are maintained, but the system complexity increases due to timing assessment logic
Solution Approach 1:
The system extracts only the essential timing information needed for legato detection - specifically whether a key-off occurs within a predetermined time period after a key-on. By focusing on this single critical parameter rather than analyzing all key operation details, the system achieves natural legato handling with minimal added complexity
Solution Approach 2:
The system changes the operational parameter of note reselection based on the detected performance mode. During legato performance, the reselection parameter is suppressed; during non-legato performance, normal reselection is enabled. This parameter switching allows the system to adapt to different performance styles without requiring completely different control logic for each case
Data Source
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AI summary
One or more assigners ( AS-1 ... AS-n ) selecting a note to be sounded ( n1, n2, n3, n4 ) according to operation state of plural controls ( 22 ) , for instance keys (22) in an electronic musical keyboard , corresponding respectively to notes are provided. The CPU decides ( 35, S17 S69, S71 ) for each of the assigners whether or not to select a note to be sounded in response to a key release (key-OFF) operation of any of the controls (22). When a key-OFF of any of the controls is detected, and presuming a performance method such as legato or staccato _ based on four conditions ( S62, S63, S64, S65 ) of timing and of Keys_ON/OFF _, the assigner ( ASi ) which is decided to select a note to be sounded, is instructed to select a note to be sounded according to operation state of the controls after the detection of the key release .