Brazilian rhythms, and what tells one from another
Samba, baião, xote, maracatu and frevo read by what distinguishes them — where the accent falls and how the pulse divides; each has a clapping pattern that fits in two bars, and that is where you start.
The same chord sequence serves a samba, a baião and a xote. What distinguishes them is not in the chart: it is in where the accent falls and in how the pulse divides, and that lives in the guitar's right hand, in the bass and in the percussion. Each rhythm has a pattern that fits in two bars of two-four and that is learned by clapping, before any score.
2/4The pulse and the subdivision
Nearly all these rhythms are written in two-four: two pulses per bar, each pulse divided into four semiquavers. The semiquavers are the ruler; the rhythm is which of them get an attack and which get an accent.
Eight semiquavers per bar, all equal: that is the shaker, the muffled tambourine, the triangle. On that ruler each genre draws its accent.
Samba
Samba accents the second pulse: the surdo marks the two, low and long, and the one stays lighter. Over that, the cell that gives the swing is semiquaver–quaver–semiquaver, accenting the middle of the pulse.
The second version, with the cell on both pulses, is the tamborim; the first, with the second pulse plain, is the guitar's right hand. What makes it samba is the accent on the two and the note crossing the middle of the beat; without both, it is a march.
Baião
Baião accents the one and the last quaver of the bar: the zabumba strikes hard on the first pulse and again on the second half of the second, and the space between them is what gives the sway.
Dotted crotchet and quaver: the accent on the one, and the second attack on the "and" of two, pulling ahead into the next bar. Above it, the triangle in semiquavers and the zabumba muffled on the two. It is the easiest clapping pattern of all and the most recognisable.
Xote
The xote is baião walking slowly, with the accent on both pulses and the subdivision dragged: the quavers are not equal, the first of each pair lasting a little longer than the second, and that is what makes the dance step.
Written down, the xote looks like a slow march; played, the quavers swing. It is a case where the score lies by omission, and the clapping pattern says more than it does: one, two, one, two, with the body going sideways on each one.
Maracatu and frevo
Maracatu de baque virado accents the one with weight, on the alfaias, and puts an answer on the last semiquaver of the bar, which pulls into the next. The tempo is medium and the sensation is of a heavy march pushing forward.
Frevo is the same writing in two-four at a very fast tempo, with the syncopation in the brass — semiquaver, quaver, semiquaver — and the bass accenting both pulses. It is Pernambuco's samba accelerated until it becomes a run, and the difference from samba is the tempo and the absence of the surdo on the two.
How to start
Not from the score. From the clapping pattern: tap the pulse with your foot and the cell with your hands, two bars, until it comes without thinking. Then transfer the cell to the guitar's right hand, keeping the song's chords; the chart does not change. Only then read the score, which will confirm what the hands already know.
What to take from here
Brazilian rhythms are told apart by accent and subdivision, not by harmony: samba accents the two and crosses the middle of the pulse, baião accents the one and the last quaver, the xote drags its quavers, maracatu weighs on the one and answers on the last semiquaver, frevo is syncopation at a run. Each fits in a two-bar clapping pattern, and that is where you start.