Tessera

Tessera is a generative firmware for the M-Vave FM-1. Each of the four tracks can play its own steps, an arpeggio, or one of thirteen generators, and the pages around them evolve the phrases, build song forms, pass hits between tracks and modulate anything from anything. GPL-3.0-only. Status: Experimental. By Theo Dainis (Rastapopolix).

Tessera grew out of Melodee (Tess), a fork of Melodee by keremimo, itself built on Felucca by Leo Kuroshita / Hügelton Instruments. Releases up to 1.3.x were published as Melodee (Tess).

Tessera (plural tesserae) is the Latin word for the small tile of stone or glass in a mosaic. Each generator makes a short phrase; EVOLVE and FORM set mutated phrases side by side into sections, so a piece is built from small tiles arranged into a larger pattern. The word also meant a die, which suits the chance-driven generators.

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Install

Flash it from your browser (Chrome or Edge, FM-1 connected directly by USB): Web installer. Afterwards you can edit sounds and sequences from the computer with the web editor.

Each release has two builds: tessera-X.Y.fwsc (standard, dual core: start here) and tessera-X.Y-1core.fwsc (single core, for FM-1s that crash with the standard build).

Do not unplug the FM-1 while it is writing. This is experimental firmware: use it at your own risk. The installer page also has a way back to the official V15 firmware, with a backup first.

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What's inside

• Thirteen generators on SEQ > GEN: TURING, EUCLID, MARKOV, MORPH, ATLAS (with a fourth drum part), BOUNCE (and FALL), AWAKE, POLY, QUAD, CONSTELLATION, SERIES, CHORD and ANSWER, besides the step sequencer and the arpeggiator.
• Shaping: EVOLVE mutates a phrase every few bars, and STEP EVOLVE does the same to steps you wrote; FORM builds sections such as AABA; TWEAK shifts, drops, humanises or follows another track; TWEAK 2 branches hits to another track's sound, combines tracks with logic, and plays only on certain bars; LENGTH sets how long notes hold.
• Harmony: one key and scale for the whole project (Key link); a CHORD track plays a progression (or your own), and QNT CHRD makes the other tracks follow it.
• Modulation: 16 cords from any source to any destination on any track, generators included; slow organic sources (TIDE, SWARM); live marks on every knob a cord moves, and MATRIX to see the whole patch.
• Print: hold REC to turn what a generator played into ordinary steps.
• Sounds: FM6 (six-operator FM, three engine models), TRIO and DRUM (808, 909, SID KIT).
• MIDI OUT of every track and the generators, each on a channel of its own (GLO > MIDI OUT), and CLOCK OUT, over USB.
• Its own look: the SMALTI palette, square tiles, Chakra Petch, and an animated mosaic splash.

The manual covers every page, knob and shortcut; RECIPES.md has step-by-step patches and tips.

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Gallery

The pages as the firmware draws them, rendered on the host from the firmware's own drawing code (tests/gallery_render.c) in the default SMALTI palette, shown at 2x.

More pages are in the manual.

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Building

See BUILDING.md. The host tests run with tests/run_tests.sh; the gallery renders with tests/gallery_render.c (build line at its top) and the banner and social preview with tools/gen_brand.py.

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About me

I'm Theo Dainis, from New Zealand. I've been using and building synthesisers for the past 15 years, and I'm passionate about modular and open source. Elektron and Mutable Instruments are big influences on me. I love the DIY side: building things, and learning how music hardware works on the inside. Tessera is the sequencer I wanted on the FM-1: modular in a box, a small instrument that writes with you.

Built with Claude Code

Tessera's code is written with Claude Code, Anthropic's AI coding tool. I designed it, made the decisions, and test every release on my own FM-1 before it goes out. The source is open, so you can read every line and every change. Like any firmware, it comes with no warranty: save a Complete backup from the web editor before you flash.

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Credits and licence

Tessera is by Theo Dainis (Rastapopolix). GPL-3.0-only, inherited from Melodee. Original copyright and SPDX headers are preserved. Melodee is by keremimo, Felucca by Leo Kuroshita / Hügelton Instruments.

The ATLAS generator uses the drum map of Grids by Émilie Gillet / Mutable Instruments. Several generators are inspired by norns scripts (ideas only, no code copied): QUAD by initenere, FALL by ambalek's Fall, CONSTELLATION by timothy-taylor's Constellation, AWAKE by tehn's Awake and SERIES by nørgård. The The TIDE and SWARM mod sources are inspired by Triple Sloth by Nonlinear Circuits (Andrew Fitch) and ochd by Instruō and DivKid. See LICENSING.md for every third-party part and its licence.