Appendix E — Free Resources

Everything this book’s records were built with that you can download today for nothing. URLs current as of publication; the names are stable enough to search if a link drifts.

Sound sources

GeneralUser GS — the General MIDI soundfont behind Chapter 2. Free, ~30 MB, all 128 programs at consistent levels. → schristiancollins.com/generaluser.php
FluidR3 GM — the soundfont Ubuntu ships as the fluid-soundfont-gm package; a fine alternative.
TimGM6mb — a tiny (6 MB) GM soundfont, handy for tests and CI; it ships inside the pretty_midi pip package, which makes it the most reliably downloadable soundfont in existence: python import pretty_midi, os, shutil shutil.copy(os.path.join(os.path.dirname(pretty_midi.__file__), "TimGM6mb.sf2"), "TimGM6mb.sf2")

Amps and effects

Neural Amp Modeler (plugin) — the free VST3/AU that plays .nam amp captures. → neuralampmodeler.com
Tone Hunt — the community library of thousands of free .nam captures; the AC15, Twin, and dUg bass preamp on this book’s records all came from community captures. → tonehunt.org
Voxengo free impulse responses — the measured rooms behind Chapter 11, including the drum room on the darkwave record. → voxengo.com (Impulse Modeler / free IR pack)
OpenAIR — academic library of measured spaces (churches, concert halls) under permissive licenses; the featured-space IRs.

Drum machines

smpldsnds/drum-machines — one-shots from dozens of hardware boxes; all eight machines in Chapter 6 (LinnDrum LM-2, Drumtraks, TR-808, CR-8000, RZ-1, MFB-512, MR10, SK-1) came from here. → github.com/smpldsnds/drum-machines

Python libraries

library	role in the book
`pedalboard`	plugin hosting + built-in effects (Spotify, ch. 3–4, 10–11)
`pyfluidsynth`	the FluidSynth binding (ch. 2)
`numpy`	audio is NumPy arrays, everywhere
`scipy`	WAV I/O, filters, `sawtooth` (ch. 5–7)
`mido`	MIDI messages for instrument plugins (ch. 3–4)
`mutagen`	release metadata tagging (ch. 15)
`pretty_midi`	mostly for the soundfont in its pocket (tests)

Instruments already on your Mac

The GarageBand factory library — the several-GB sampler content Chapter 5 unlocks (Steinway, Mellotron, kits, guitars). Free with every Mac; extraction is Chapter 5, format is Appendix B, license note in both.
Ample Bass P Lite II — the free deep-sampled P-bass rescued in Chapter 4. → amplesound.net (free line)

The companion code

The complete working pipeline — every loader, the band scripts, the album engine, the audition harnesses, the stems exporter with its null test, and the CI harness that keeps the book’s claims honest — is free and open on GitHub, MIT-licensed: github.com/clintuitive/headless-studio. Code only: the sound sources above are downloads, not redistributables, which is why this appendix exists.

If a link here has rotted: the search terms in bold survive, and the book’s errata page lives at the blog — clintjohnson.cloud/headless-studio.