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. The berimbau has its own page, with its toques and the capoeira's bateria (the medio and the viola, pandeiro, atabaque, agogô, reco-reco); two drones, the tanpura and the shruti box, sound alone or under the rhythm.

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_48010000 is 1.0).

The FM-1's 240 × 240 screen: the rhythm's name at the top; an instrument's steps in its colour, a row a beat, the step playing framed in white; the tempo, the time signature and the instrument at the bottom, over the page's instruments in three letters; 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.
• Everything changes on the bar. A rhythm chosen while one plays comes in on the next bar's first beat (NEXT beside its name at the top till then, its time signature in the accent). PLAY while playing stops on the next bar's first beat, its strokes the last (PLAY blinks, a white square in the footer); PLAY again stops at once. A tempo set while playing glides there over a bar; a tapped one (SEQ) is there at once.
• Each rhythm keeps its tempo: set it once, and it comes back at it, away and back (SAVE keeps it).
• The tempo can rise. SEQ held while playing: it rises slowly and evenly, a BPM every 12 beats, as the lead of a jembe piece raises it (BPM in the accent, SEQ lit). OCT− or OCT+, or SEQ held again, keep the tempo reached; KNOB 1 or tapping end the rise at the tempo they set; stopped, or another rhythm come in, the rhythm is back at its own.
• 32 rhythms, grouped by their beats, and places for your own. ALGORITHM chooses the beats; PRESETS goes round the rhythms with those beats, each coming as it is written, then yours; an empty place is not shown.
• SAVE keeps the tempo and the sounds, and a changed rhythm where you choose. It lists the FREE places, 7 for the kit and 2 for the berimbau, each for a rhythm of any beats, EMPTY or with its time signature. KNOB 3 goes through them; SAVE puts the rhythm there, over what it holds, and it plays on from there; a page button leaves it. The written rhythms stay as they are.
• The berimbau and the capoeira's bateria (FX), played as the kit is:
  • three berimbaus, as in a roda: the GUNGA (the lowest), the MEDIO and the VIOLA, a tone up each (each one's DIM the next one's DOM, as a bateria is commonly tuned); SELECT shows each, then the caxixi, the PANDEIRO, the ATABAQUE, the AGOGÔ and the RECO-RECO, each with its steps;
  • its black keys: the berimbau shown, DOM (the wire struck free), DIM (the stone pressed on it, a tone higher), TSCH (the stone resting on it, a buzz); the caxixi and the reco-reco; the pandeiro's TUM (thumb), PA (slap) and CHIA (its jingles); the atabaque's TUM and PA (with ARP held, the agogô's high and low bells); the last, VIRADA;
  • the cabaça: a berimbau's keys pressed harder close its gourd on the belly, its sound muffled as far as the pressure goes, the "wah" of a roda (SOUND, CABACA: how far, 0 to 100 %);
  • viradas: each berimbau varies its toque now and then (SOUND, VIRADAS: every 8, 4 or 2 bars, every bar, or never; the viola every 4 at first), and VIRADA has the berimbau shown vary from the next bar. ANGOLA and SAO BENTO GRANDE de Angola play the sources' own variations, two bars each (below); the other toques a bar made from the toque, not transcribed: its DOM and DIM struck twice in the bar's second half (dobrado), its last beat all DIM (repique), or its rests filled with soft chiados;
  • the ladainha: ARP + VIRADA begins RODA ANGOLA as a roda of capoeira Angola begins, from a stop too: the gunga and its caxixi, then the medio, the viola and the pandeiro, two bars each, for the singer. Again: the chula, the atabaque, the agogô and the reco-reco on the next bar. Again: back to the base. PLAY stops as ever;
  • its toques: ANGOLA, SB PEQUENO, SB GRANDE, BANGUELA, JOGO DE DENTRO, JOGO DE FORA, RODA ANGOLA, SB REGIONAL, CAVALARIA, IDALINA and MIUDINHO, a quarter slower than a roda plays them (ANGOLA at 45 BPM, in 2/4);
  • the berimbau's strokes recorded from Paulo Gonçalves's, the caxixi's from Oldome's; the pandeiro's, the atabaque's, the agogô's and the reco-reco's synthesised (app/tools/synth.py).
• 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, their type (KNOB 3: SHAKER, CLASSIC, GOURD, DAIME);
  • triangle: level, ring;
  • gunga, medio, viola: level, tuning (its wire), cabaça, viradas;
  • atabaque: level, tuning;
  • clapsticks, caxixi, agogô, pandeiro, reco-reco: 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. Their two takes alternate, each beat starting on the first, so the beats stay alike.
• One control per setting:
  • SELECT: the instrument.
  • SEL: mute.
  • EDIT twice: clear.
  • SEQ: tap tempo; held, the tempo rises.
  • SAVE: keep the settings; a changed rhythm, in the FREE place you choose.
  • FX: the kit, the tanpura, the shruti box, the berimbau.
  • OCT− / OCT+: the tempo, 5 BPM a press, 10 held.
  • HOME: the steps; KNOB 1 the tempo (40 to 240, the berimbau's page 20 to 120), KNOB 2 the steps a beat, KNOB 3 the swing, KNOB 4 the human feel.
  • ENV: the instrument's SOUND page.
  • GLO: SETUP; KNOB 1 the click, KNOB 2 the count-in, KNOB 3 the keys' lights, KNOB 4 the velocity.
  • MASTER: the volume.
  • LFO: the presets listed, with their beats (the number at the right; a toque's, its counts), 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 (FX), alone or under the rhythm. On a drone's page, PLAY stops the drone if it sounds; else it stops the rhythm if one plays (on the next bar's first beat; again: at once); else it starts the drone. For a drone under the rhythm, start the drone first: its PLAY, then HOME (on its page) goes back to the kit, the drone sounding on, and the kit's PLAY starts the rhythm. FX leaves the kit playing on under a drone's page. One drone at a time; the berimbau's page stops the kit, not the drone.
  • 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; EDIT twice closes them all. 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; under 20, the rhythm's tempo, halved above 120: "= 66 BPM"), KNOB 3 the level. A bar under the reeds shows the bellows breathing.
  • Both are synthesised as they play: no samples.
• A minimal screen, large type, a colour per instrument. At the top, the rhythm's name. At the bottom, the tempo, the bar's time signature (its beats over 4; beats of three steps, their eighths over 8: 6/8, 12/8) and the instrument shown, in its colour. Under them, the page's instruments in three letters (DJE CAJ UDU CLA MAR TRI; GUN MED VIO CAX PAN ATA AGO REC), always in their order: in their colour when they play in the rhythm, dark when not, white as they strike, grey muted; the one shown taller; a drone sounding under it, last. The berimbaus' steps read DOM, DIM, TCH. The berimbau's page shows the toques as their sources count them, in 2/4, the tempo its quarter note: ANGOLA at 45 BPM, its grid a row a count, four to the bar (eight, over two bars). 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, for 5 s after the opening, 3 s after HOME or FX, and all the time with one bar left or none: 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

Beats	Rhythms
2	HEARTBEAT, BAIAO, XOTE, SAMBA, MARCHA 2/4, DAIME MAZURCA, BARRAVENTO, JOROPO
3	THREE, DAIME VALSA, TOADA
4	FOUR, JOURNEY, SHAKER, CLAVE, AFRO 12/8, DAIME MARCHA, IJEXA, IJEXA CANTO, KUKU, AFRO SAMBA, BOSSA NOVA, FUNK IJEXA, SAMBA DJEMBE, XOTE DJEMBE, DJOLE, YANKADI
5	FIVE
6	LANDO, BULERIAS
7	SEVEN
8	AFOXE

The berimbau's toques:

Counts	Toques
4	ANGOLA, SB PEQUENO, SB GRANDE, BANGUELA, JOGO DE DENTRO, JOGO DE FORA, RODA ANGOLA
8	SB REGIONAL, CAVALARIA, IDALINA, MIUDINHO

Where they come from:

• Santo Daime, the maracá: DAIME MARCHA (f f f F), DAIME VALSA (F F f), DAIME 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 counts. 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.
• The roda of capoeira Angola (RODA ANGOLA): the gunga plays ANGOLA, the medio SÃO BENTO PEQUENO and the viola SÃO BENTO GRANDE de Angola, as the Companhia Pernas Pro Ar's "Toques de Berimbau" (2023) and Capoeira Baobá (2026) give them. The pandeiro and the atabaque as Elias's Só Ritmo (Grupo Capoeira Brasil, 2017) writes their capoeira grooves; the agogô and the reco-reco as Wikipedia's "Capoeira music" has them (uncited there). Sources disagree on the atabaque (Wikipedia's open tones are Só Ritmo's basses).
• The ladainha: the order of the entries, Liliana V. Xavier, "O canto que embala a roda de capoeira angola" (Revista África e Africanidades 10, 2010). It varies between groups; the two bars each and the way back to the base are ours.
• The tempo rising: Rainer Polak, "Rhythmic Feel as Meter" (Music Theory Online 16.4, 2010): a piece from 135 to 205 BPM in 218 cycles, a nearly constant rise. Our rate is that one's, on both pages; the source is about the jembe.
• The viradas: ANGOLA's, the viola's "common variations" in Wikipedia's "Capoeira toques"; SÃO BENTO GRANDE de Angola's, Só Ritmo's "Viradas".
• 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 or take. app/tools/kit.py build turns them into app/dsp/kit_samples.c (about 408 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.

Instrument	Source	Licence
Cajon, clapsticks (claves), maracas' SHAKER (a large shaker's hits), triangle	VCSL, the Versilian Community Sample Library, by Versilian Studios	CC0 1.0
Maracas' CLASSIC	"Two Big Maracas shakes - Multi-takes" by Sadiquecat, cut from its public preview	CC0 1.0
Maracas' GOURD	"Pataxó's Maraca" by REVERBERA, cut from its public preview	CC0 1.0
Maracas' DAIME	recorded by Jess Del Rio, cut	free to use
Udu, bass	"122-Udu" by klemmy	CC BY 3.0
Udu, tone and slap	"Pong Pop" by AncientOracle, cut	CC BY 4.0
Berimbau (DOM; DIM, a tone higher and damped; TSCH, damped)	"Berimbau_03", "Berimbau_01" and "Berimbau_02" by Paulo Gonçalves, cut	CC BY 4.0
Caxixi	"Musical, percussion, caxixi, shake…" by Oldome, cut	CC0 1.0
Djembe; agogô, pandeiro, atabaque, reco-reco	synthesised by app/tools/synth.py
Medio, viola	the berimbau's strokes, played 2 and 4 semitones higher	CC BY 4.0

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.