FM-1_DelRio: a ceremony rhythm box for the M-VAVE FM-1

A firmware that turns the M-VAVE FM-1 into a small rhythm box of hand percussion, made to accompany songs in a circle: djembe, cajon, udu, clapsticks, maracas and triangle. Choose a rhythm, set the tempo, press PLAY and sing; or play the instruments on the keys, record them into the loop, and shape them step by step. Three more instruments are each played alone: the berimbau with its toques, and two drones, the tanpura and the shruti box.

By Jess Del Rio. Its splash screen says DEL RIO; its USB name is "FM-1 DelRio", its identity FM-1_48 and the version (FM-1_48000200 is 0.2).

The FM-1's 240 × 240 screen: an instrument's steps in its colour, a row a beat, the step playing framed in white; the tempo, the beats and the rhythm at the bottom; a page of large sliders. All the screens.

What it does

• Six instruments, with their real strokes. Djembe (bass, tone, slap), cajon (bass, slap), udu (bass, tone, slap), clapsticks, maracas, triangle (open, muted).
• The black keys play them, grouped as the keys are:
  • djembe bass, tone, slap;
  • cajon bass, slap;
  • udu bass, tone, slap;
  • clapsticks, maracas;
  • triangle. Harder is louder.
• The white keys are a step sequencer for the instrument shown. Each press puts that step's next stroke, and after the last, none. A bar has 2 to 8 beats of 2, 3 or 4 steps; when it is longer than the 16 keys, they follow the step sounding.
• PLAY loops the rhythm; REC records what you play on the black keys, each stroke onto the nearest step, over what is there. From a stop, a bar is counted in first. The sequencer runs in the audio interrupt, to the sample.
• 39 rhythms, grouped by their beats. ALGORITHM chooses the beats; PRESETS goes round the rhythms with those beats, each coming as it is written. Each number of beats has a FREE rhythm of your own.
• The berimbau, played alone (FX), as the kit is played:
  • its black keys: DOM (the wire struck free), DIM (the stone pressed on it, a tone higher), TSCH (the stone resting on it, a buzz), then the caxixi; the same again, for the other hand;
  • its toques: ANGOLA, SB PEQUENO, SB GRANDE, BANGUELA, JOGO DE DENTRO, JOGO DE FORA, SB REGIONAL, CAVALARIA, IDALINA and MIUDINHO, and two FREE ones, a quarter slower than a roda plays them (ANGOLA at 90: its quarter note at 45);
  • SELECT: the berimbau or its caxixi, each with its steps;
  • the strokes recorded from Paulo Gonçalves's berimbau.
• Only what a player can change. Each instrument's SOUND page has only what is real for it:
  • djembe: level, tuning (its ropes), decay (a hand on the head);
  • cajon: level, snare wires (down to off), decay (a heel on the front);
  • udu: level, size (tuning), how far a pressed key lowers the bass (a palm closing the opening);
  • maracas: level, a short or long shake;
  • triangle: level, ring;
  • berimbau: level, tuning (its wire);
  • clapsticks, caxixi: level.
• Played like the instruments.
  • The triangle rings while its key is held, and the hand closes on it when let go. A short tap is a muted stroke.
  • Pressing the udu's bass key harder lowers its pitch.
  • With ARP held, the djembe's strokes are flams.
  • The maracas are one pair of hands, so a stroke stops the one before.
• One control per setting:
  • SELECT: the instrument.
  • SEL: mute.
  • EDIT twice: clear.
  • SEQ: tap tempo.
  • SAVE: keep everything.
  • FX: the kit, the berimbau, the tanpura or the shruti box.
  • OCT− / OCT+: the tempo, 5 BPM a press, 10 held.
  • LFO: the presets listed, with their beats, from the one chosen; the list stays, KNOB 3 goes through it without changing anything; LFO held chooses the one shown, LFO again closes the list.
• Two drones, each played alone (FX):
  • TANPURA: four strings plucked in turn (Pa – Sa – Sa – low Sa), buzzing on their bridge (the jawari). A key sets Sa; ALGORITHM tunes the first string (SA PA, SA MA for the ragas without Pa, SA NI); PRESETS sets its character: MEDITATION (slow, a soft jawari), MANTRA (round), RAGA (the concert tanpura's open jawari), KIRTAN (quicker, brighter). KNOB 1 the jawari, KNOB 2 the cycle, KNOB 3 the register, KNOB 4 the level.
  • SHRUTI: the shruti box's reeds, held while the bellows breathe. PRESETS: the chord a key plays, SA PA (root, fifth, octave), MAJOR or MINOR; or NOTES, each key opening or closing its reed. The bellows go back and forth in time: KNOB 1 how strongly they breathe (steady at 0; at the most the sound falls away where the hand turns), KNOB 2 their tempo (a push, then a pull, each a beat), KNOB 3 the level.
  • Both are synthesised as they play: no samples.
• A minimal screen, large type, a colour per instrument. At start, a maned wolf (the lobo-guará of the cerrado) walks into the cerrado at dusk, in big pixels (80 x 80, 32 colours), his four legs stepping in turn, and stops before the setting sun; a key, a button or a knob skips it. The pictures are Jess Del Rio's (app/art/); app/tools/opening.py makes the scene and cuts the wolf out.
• The battery, top right: three bars, the outline red when it is empty; USB while a computer powers the FM-1. The keys' velocity holds the converter that reads it, so every 10 s, with no key down, it is let go for 2 ms.
• A screen reader can follow it (fm1-reader, over USB).

The rhythms

The berimbau's toques:

Where they come from:

• Santo Daime, the maracá: MARCHA (f f f F), VALSA (F F f), MAZURCA (6/8, f f f F F F), as described by the Jornal Grande Bahia, "Abaixo o maracá. Viva o maracá" (2016).
• Umbanda, the atabaque on the djembe (Tum its bass, Ta its tone): IJEXA ("Ta TaTa Tum Ta") and BARRAVENTO ("Tum TaTa TumTum", 6/8), from the Templo Tata Possum's Curso de Atabaque (2024).
• Brazil:
  • BAIAO: the zabumba, and the triangle closed with the off-beats open (ANPPOM 2018).
  • SAMBA: the surdo and the ganzá.
• Each instrument's own:
  • KUKU: the Mandinka djembe's accompaniment, "B.TT..S.B.TT..S." (M. Gąsewicz, "A rhythm notation for djembe and dundun drums", BachoTeX 2023).
  • LANDO: the Afro-Peruvian cajon, "B . F . B B | . F B . F B" in 6/4, F a flam (Wikipedia, "Landó (music)"; Thomann's cajon guide).
  • BULERIAS: the flamenco cajon's slaps on the compás's accents, 3, 6, 8, 10 and 12 of 12 (K. Kocoshis, Percussive Notes, 2025).
  • JOROPO: the llanero maracas, six eighths accented as 6/8 (Radio Nacional de Colombia).
• Brazil's on the djembe: AFOXE (two bars), AFRO SAMBA, BOSSA NOVA, FUNK IJEXA, SAMBA DJEMBE and XOTE DJEMBE, as the djembegorilla.com library writes them, in sixteenths (its muted tones and taps are soft tones here).
• West Africa's: DJOLE (the Temine's mask dance: its third djembe part, the kenkeni's bell on the clapsticks, the dundunba on the cajon) and YANKADI (the Sousou's slow dance: its first djembe part, the dundunba's bell on every pulse), from Paul Nas's box notations, West African Percussions.
• The urban neo-ayahuasca circles: IJEXA CANTO, XOTE, MARCHA 2/4, TOADA, and BAIAO's djembe are the grooves they play on the djembe under their cantos. They are practical adaptations, not canonical transcriptions: the Huni Kuin's own cantos are carried by the voice, with a maracá at most.
• The berimbau's toques, as the Cordão de Ouro teaches them (Toques do berimbau, Flensburg 2020): counted "0 – 1 – 2 – 3", the two chiados (TSCH) on 0, then the DOM and the DIM on the beats. SB REGIONAL is Mestre Bimba's, over two counts: "tsch tsch DOM, tsch DIM, tsch tsch DOM DOM DIM". JOGO DE FORA (Jogo de Dentro turned over), CAVALARIA (whole: "tsch tsch DOM, tsch DOM, tsch tsch DOM DIM DOM"), IDALINA and MIUDINHO follow opencapoeira.com's notations, its | a chiado, || two.
• Choosing for a canto such as Jiboia, by ear:
  • IJEXA CANTO when it drags and sways;
  • BAIAO or MARCHA 2/4 when it pushes you to dance;
  • TOADA when it is ternary.

Install

From The Firmware Hub, or with the .fwsc of the latest release.

It keeps only its own settings and rhythms (SAVE), in its own place in the FM-1's flash. It does not read other firmwares' projects or samples.

The sounds

app/kit/ holds one WAV per stroke. app/tools/kit.py build turns them into app/dsp/kit_samples.c (about 233 KB of the FM-1's flash: 8 bits a sample, in blocks of 16 that each keep their own scale, the noise about 44 dB under each block's loudest). The tanpura and the shruti box use no samples: they are synthesised as they play.

Any stroke can be replaced by your own recording: drop a WAV named after it (djembe_bass.wav, triangle_muted.wav…) into app/kit/ and run app/tools/kit.py build.

Licence

The code is under the Mozilla Public License 2.0 (LICENSE), as fm1-base is. The sounds keep their own licences (above, and app/kit/CREDITS.txt).

It is built on fm1-base by Charles Vestal and on felucca-bsp, from Felucca by Leo Kuroshita (Hügelton Instruments). M-VAVE and FM-1 are trademarks of their owners; this firmware is not affiliated with M-VAVE.