A batida is a fixed repeating right-hand pattern: which eighth notes get a down stroke, which get an up stroke, which get a mute — the chop — and which are left silent, one bar at a time. It is not a chord diagram, because the shape underneath barely moves while the batida runs. It is not a strum count, because a mute is a note in its own right, struck and silenced in the same motion. It is the layer a cavaquinho contributes to a samba or choro roda, and it is the layer no other instrument in this network has, which is why it gets an engine rather than an essay.
The three cells
Every column below is derived: slot strings come from the pattern data (D is a down stroke, U an up stroke, M a mute, and · a declared rest), and each page's ringing pitch set is computed from the instrument's real open-string tuning plus the voicing under the hand.
| Cell | Slots | Downs | Ups | Mutes | Rests |
|---|---|---|---|---|---|
| The samba cell | D-M-U-M-D-M-U-M | 2 | 2 | 4 | 0 |
| The teleco-teco cell | D-U-D-M-U-D-U-M | 3 | 3 | 2 | 0 |
| The choro cell | D-·-U-D-·-U-D-· | 3 | 2 | 0 | 3 |
The mute rule
A mute is not a rest, and the engine never confuses the two. Both are declared explicitly in the pattern data, but a rest is silence with nothing happening, while a mute is the hand striking every string with the fretting hand (or the picking-hand edge) damping them first — a percussive click with no pitch, the chop the roda counts time by. That is the honest difference between a batida and a picking pattern: a figure that rests leaves a gap, while a batida that mutes fills the gap with a sound that just has no pitch attached to it.
Where to start
Learn the choro cell first, even though the samba cell is the famous one: no mute anywhere in its bar, so the whole hand can focus on evenness before it has to add a chop on top. Then the samba cell, whose four mutes are where beginners rush and clip the ring of the down and up strokes around them. The teleco-teco cell comes last — it is the busiest of the three, and busy is only playable once your hand already trusts the pulse. Run each one through the chord library and keep the metronome honest underneath you.