maystudios MIDI Synth
Synthesize MIDI/MusicXML to audio and generate Strudel live-coding patterns. Uses analysis data for ghost-note cleaning, correct tempo, and key-aware filtering.
Scripts
scripts/to_strudel.py-- MIDI/MusicXML to Strudel patterns with duration-aware notationscripts/render.py-- MIDI/MusicXML to WAV/MP3 with cleaning and modifications
Both scripts auto-detect *_analysis.json files from audio-to-midi for tempo, key, and dynamics.
Workflow
- Identify input: MIDI (.mid) or MusicXML (.musicxml)
- Auto-detect or specify the analysis JSON from audio-to-midi
- Choose workflow:
- Creative:
to_strudel.pygenerates Strudel code for strudel.cc - Rendering:
render.pyproduces WAV/MP3 - Both: run both on the same input
- Creative:
- Ghost notes are automatically cleaned using velocity, duration, and key filters
Strudel Code Generation
# Basic (auto-detects analysis JSON next to input)
py -3.12 scripts/to_strudel.py "song.mid"
# From MusicXML
py -3.12 scripts/to_strudel.py "song.musicxml"
# Explicit analysis file
py -3.12 scripts/to_strudel.py "song.mid" --analysis "song_analysis.json"
# Stricter ghost-note filtering
py -3.12 scripts/to_strudel.py "song.mid" --min-velocity 60 --min-duration 0.1
# Open in browser
py -3.12 scripts/to_strudel.py "song.mid" --open
| Flag | Default | Effect |
|---|---|---|
--analysis |
auto-detect | Path to analysis JSON for tempo/key |
--bars |
4 | Pattern length in bars |
--resolution |
16 | Grid: 4/8/16/32 |
--min-velocity |
40 | Remove notes below this velocity (0-127) |
--min-duration |
0.05 | Remove notes shorter than this (seconds) |
--no-key-filter |
off | Disable key-based ghost note filtering |
--tempo |
from analysis | Override tempo BPM |
--open |
off | Open in strudel.cc in browser |
Note durations are encoded with @N notation (e.g., c3@4 = held for 4 steps).
Audio Rendering
# Basic (auto-detects analysis, cleans ghost notes)
py -3.12 scripts/render.py "song.mid" --mp3
# From MusicXML
py -3.12 scripts/render.py "song.musicxml" --mp3
# With SoundFont
py -3.12 scripts/render.py "song.mid" --soundfont "GeneralUser_GS.sf2" --mp3
# Aggressive cleaning
py -3.12 scripts/render.py "song.mid" --min-velocity 60 --min-duration 0.1
# Skip cleaning entirely
py -3.12 scripts/render.py "song.mid" --no-clean
# Modifications
py -3.12 scripts/render.py "song.mid" --tempo 2.0 --transpose 3 --instrument 0
| Flag | Default | Effect |
|---|---|---|
--analysis |
auto-detect | Analysis JSON for tempo/key-based cleaning |
--min-velocity |
40 | Ghost note velocity threshold |
--min-duration |
0.05 | Ghost note duration threshold (seconds) |
--no-clean |
off | Skip ghost note removal |
--no-key-filter |
off | Disable key-based filtering |
--soundfont |
auto-detect | .sf2 SoundFont path |
--tempo |
1.0 | Tempo scale factor |
--transpose |
0 | Semitones up/down |
--instrument |
original | Override GM program (0-127) |
--mp3 |
off | Also produce MP3 |
Ghost Note Cleaning
Three filter layers (applied in order):
- Velocity filter: removes notes below
--min-velocity(default: 40) - Duration filter: removes notes shorter than
--min-duration(default: 50ms) - Key filter: if analysis provides a key, removes out-of-key notes that also have low velocity (<60)
The key filter only removes notes that are BOTH out-of-key AND below medium velocity, preserving intentional chromatic passages.
Dependencies
Auto-installed: pretty_midi, numpy, soundfile.
For MusicXML input: music21 (installed by audio-to-midi skill).
Optional: pyfluidsynth + .sf2 SoundFont for high-quality rendering.
Runtime: Python 3.12 (py -3.12).