Python : MIDI Data & Text Practice

[kimpro82]

1. Overview

• Objective: Understand the structure of MIDI data in a Python environment without an external DAW, and directly create, edit, and play the song [School Bell] using bidirectional JSON and ABC notation formats.
• Target Audience: Developers and music data processing beginners who want to learn the principles of converting binary music data into human-readable text formats through programming.

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2. Core Features

2.1. JSON-based MIDI Parser & Builder (JSON Pipeline)

• Binary to JSON Conversion: Parse existing MIDI files (.mid) containing metadata and events (note_on, note_off, tempo, etc.) into structured JSON text.
• JSON to Binary Compilation: Modify note values (velocity, delta times, etc.) within the JSON structure programmatically and recompile them back into standard MIDI binary files.

2.2. ABC Notation-based Text Editor (ABC Pipeline)

• Text Score Loading: Load ABC text format files (.abc) containing aligned melodies and lyrics for [School Bell].
• Parsing & Validation: Parse the 1:1 matching structure between musical notes and lyric syllables, including validation checks for note-to-syllable consistency.
• MIDI Conversion: Convert the parsed ABC data into MIDI byte streams using specialized processing libraries.

2.3. Built-in Audio Playback Engine

• Real-time Rendering & Playback: Utilize Python's internal sound engines or virtual synthesizers (e.g., pygame.mixer) to instantly output the generated MIDI file as audio without an external DAW.
• Playback Controls: Support basic controls such as start (play), stop (stop), and loop playback.

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3. Tech Stack

• Language: Python 3.x
• MIDI Processing: mido (Binary and message manipulation), music21 (ABC notation parsing and MIDI conversion)
• Audio Playback: pygame (MIDI sound output and synthesizer execution)
• Data Formats: .json, .abc, .mid

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4. Implementation Milestones

1. Phase 1 (Environment Setup & Sample Preparation):
   • Install required Python libraries (mido, pygame, music21).
   • Create JSON structure templates and .abc text files for [School Bell].
2. Phase 2 (JSON Pipeline Implementation):
   • Write scripts to read JSON files, convert them into mido objects, and play them via pygame.
3. Phase 3 (ABC Pipeline Implementation):
   • Implement an ABC parser including alignment exception handling for lyrics (w:) and notes, followed by MIDI file generation.
4. Phase 4 (Integration & Verification):
   • Final testing to ensure both formats (JSON and ABC) successfully generate and play the exact same melody.