Electronic Keyboard Sound Layering for Full-Range Expressive Playing

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Solution Overview

Problem

The split function in electronic keyboards limits the available range of keys, reducing the expressiveness of music playback.

Innovation Solution

A system that allows for the division of the keyboard into two areas with different sound sources, enabling the emission of distinct tones based on single and simultaneous key presses, and includes tone modification and switching functions to enhance expressiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the keyboard is divided into left and right parts with different tones (split function), then different tones can be allocated to left and right keyboard parts, but the number of keys allocated to each range is reduced, limiting the available range

Engineering Contradiction:
Improvetone allocation flexibilityVSAvoidkey range
Core Design Contradiction:
Adaptability or versatilityVSLength of moving object

Solution Approach 1:

The patent makes the entire keyboard available for both melody and accompaniment purposes. When chord playing is detected on any key, the system automatically generates accompaniment tones while allowing the same key to serve as melody input, thus the full keyboard range is utilized without the need for physical division into separate ranges.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent adds a vertical dimension of sound layering by generating multiple accompaniment tones (bass, chord, etc.) in addition to the pressed key's melody tone. This allows the full keyboard range to be used for melody while automatically providing harmonic support, effectively expanding the functional range without physical keyboard division.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If the keyboard is divided into two ranges for split function, then mutually different tones can be allocated, but the expressiveness of music playback is reduced

Engineering Contradiction:
Improvetone allocation flexibilityVSAvoidmusic expressiveness
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The system automatically detects chord playing patterns and generates appropriate accompaniment tones without requiring the player to manually switch modes or perform additional operations. The same key press that produces melody automatically triggers the accompaniment function, making the system self-serve the expressive needs of the player.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent dynamically adjusts the accompaniment tones based on the detected chord structure and playing context. The system can adaptively change the bass tone, chord tone, and other accompaniment elements in real-time based on the melody input, providing expressive flexibility without requiring physical keyboard reconfiguration.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If automatic chord detection and tone generation is implemented, then highly expressive music playback is enabled, but the system complexity increases

Engineering Contradiction:
Improvemusic expressivenessVSAvoidsystem structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The system continuously monitors key press patterns and provides real-time feedback by generating appropriate accompaniment tones. The detection unit identifies chord structures from melody input, and the tone generation unit responds by producing complementary bass and chord tones, creating a closed-loop system that adapts to player input without requiring complex manual control.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent pre-establishes tone generation rules and chord structure databases that enable automatic accompaniment. By preparing the tone generation algorithms and musical theory data in advance, the system can rapidly respond to chord detection without requiring complex real-time computation during performance, thus managing system complexity.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4131251B1Electronic musical instrument, electronic musical instrument sound emission instructing method and program
Publication Date: 2025.07.02 CASIO COMPUTER CO LTD
  • EP4131251B1 patent drawingFigure 1
  • EP4131251B1 patent drawingFigure 2
  • EP4131251B1 patent drawingFigure 3

AI summary

An electronic instrument includes a plurality of music-playing operators which designates pitch data in accordance with a music-playing operation and at least one processor which instructs a sound source which generates music sounds to emit sounds, in which the at least one processor, in a case where the music-playing operation meets a first instruction condition, instructs the sound source to emit the sound in a first sound emission form which corresponds to pitch data which meets the first instruction condition which is designated in accordance with the music-playing operation, and in a case where the music-playing operation meets a second instruction condition which is different from the first instruction condition, instructs the sound source to emit a sound which is different from the sound which is emitted in the first sound-emission form, that is, in a second sound-emission form which corresponds to pitch data which meets the second instruction condition which is designated in accordance with the music-playing operation.