Automatic Composition Apparatus Key Judgment via Scale Degree Analysis
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Solution Overview
Problem
Existing music composition technologies struggle to handle modulation in motif melodies, mode-like melodies, and atonal motifs, and often fail to achieve accurate key judgments due to their reliance on pitch distribution methods.
Innovation Solution
An automatic composition apparatus and method that includes a motif input unit, a chord-progression selecting unit, an accompaniment/chord-progression database, and a melody generating unit, which calculates matching levels between input motifs and chord progression data items using available note scales and pitch class sets to select suitable chord progressions and generate melodies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If pitch distribution method is used for key judgment, then the process is simple, but accurate correspondence relation cannot be obtained for modulation and atonal motifs
Solution Approach 1:
The patent transforms the key judgment approach from pitch distribution analysis to scale degree analysis. Instead of counting pitch frequencies, the system converts pitches to scale degrees relative to a reference tone and evaluates matching levels against stored scale patterns, enabling accurate identification of modulation and atonal motifs while maintaining computational efficiency
Solution Approach 2:
The patent replaces the statistical pitch distribution method with a music theory-based scale matching method. By substituting the mechanical counting process with theoretical scale degree analysis, the system achieves both accuracy for complex motifs and computational simplicity through standardized scale patterns
2Measurement precision
If scale degree analysis is used for key judgment, then accurate key correspondence can be obtained, but the process becomes more complex
Solution Approach 1:
The patent performs preliminary conversion of input pitches to scale degrees relative to a reference tone before matching. By pre-processing the pitch data into scale degree sequences and storing reference scale patterns in advance, the system simplifies the subsequent matching process while maintaining high accuracy for key judgment
Solution Approach 2:
The patent changes the analysis parameter from absolute pitch values to relative scale degrees. This transformation reduces the complexity by normalizing all pitches to a common reference frame, allowing the system to handle modulation and atonal motifs through standardized scale patterns without increasing computational burden
3Productivity
If chord progression database is used, then chord selection is efficient, but cannot handle modulation and mode-like melodies accurately
Solution Approach 1:
The patent creates a multi-functional chord progression database that stores progressions in multiple keys and modal variations. By organizing chord progressions with reference tones and scale degree relationships, the system can efficiently retrieve and transpose progressions to match modulation and mode-like melodies while maintaining database lookup efficiency
Solution Approach 2:
The patent makes the chord progression selection dynamic by calculating matching levels between input motif scale degrees and database progressions. The system adapts the chord selection process to the specific characteristics of each input motif, enabling accurate handling of modulation and atonal elements while maintaining efficient database query performance through structured data organization
Data Source
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AI summary
An automatic composition apparatus includes a processing unit. The processing unit performs (i) a calculation process of calculating a matching level of each chord progression data item for a motif including a plurality of note data items, with reference to a plurality of note connection rules each of which defines a connection relation of consecutive note types, and (ii) a melody generating process of generating a melody based on the motif and the chord progression data items which matching levels are calculated.