Midi synth

Skill maystudios/claude-skills/midi-synth

Production-ready Claude Code skills for Unreal Engine 5, llama.cpp, and OpenCode CLI integration. Built by maystudios.

Install

npx -y skills add maystudios/claude-skills --skill midi-synth

Assembled from the repository path, not quoted from the project. Check it against their README if it does not work.

One thing to look at

13 stars13 stars. Stars are a popularity signal and not a quality one, but at this level it is likely that nobody has read this closely except its author, and you would be relying on your own review.

What its author says it does

Copied from the file, not written here

Synthesize and render MIDI/MusicXML files to audio (WAV/MP3) and generate Strudel live-coding patterns for creative music manipulation. Uses analysis data (tempo, key, chords, dynamics) from audio-to-midi for intelligent ghost-note removal and accurate reproduction. Two workflows: (1) Convert MIDI/MusicXML to Strudel/TidalCycles code with note durations for interactive tweaking in the browser at strudel.cc, (2) Render MIDI/MusicXML to WAV/MP3 with FluidSynth or built-in synthesis, with controls for tempo, transposition, instrument override, and ghost-note cleaning. Trigger when the user wants to: play a MIDI file, render MIDI to audio, synthesize MIDI, convert MIDI to Strudel code, create live-coding patterns from MIDI, change instruments, transpose or tempo-shift, clean ghost notes, or any MIDI playback/synthesis task.

SKILL.md

4.6 KB, as published. Nobody here has run it

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 notation
scripts/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.py generates Strudel code for strudel.cc
- Rendering: render.py produces WAV/MP3
- Both: run both on the same input
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).