INTRODUCTION TO RHYTHMS
Multicultural Mathematics
Dr. Rachel Hall

The following rhythm comes from Larry Morris's Rhythm Catalog, with sounds from SongTrellis:

KAKI LAMBE (Senegal), Richard Darsie (darsie@cs.ucdavis.edu)

_               _       _       _               _
LOW CONGA    |:  O   O   .   O   O   .   B   . | O   .   O   .   B   .   B   .  :|
|:  _           _           _     | _       _               _      :|
MIDDLE CONGA |:  B   .   .   O   O   .   S   . | B   .   O   .   O   .   S   .  :|
|:  _           _           _     | _           _           _      :|
HIGH CONGA   |:  B   .   O   O   O   .   S   S | B   .   O   O   O   .   S   S  :|
|:                                |                                :|
BELL         |:  .   .   .   x   .   .   x   . | .   .   .   .   x   .   x   .  :|
JUNJUN       |:  B           B                 | B       B                      :|

Vocabulary

The BEAT is the smallest unit of time used in a piece.  Each beat has the same length.  Beats are measured in BEATS PER MINUTE, or BPM.  Higher numbers of BPM mean that the music is faster.  Compare the Kaki Lembe rhythm at 100 BPM with the rhythm at 180 BPM.

In the Kaki Lambe rhythm above, each beat is indicated by either a letter, indicating a HIT, or a period (.), indicating a REST when the drum is not sounded.  For example, the bell plays

.    .    .    x    .    .    x    .

meaning

rest rest rest hit  rest rest hit  rest

The reason that different letters are used is that each drum may be hit in a number of different ways:  on the side, in the middle, etc, and each way of hitting the drum produces a different sound.

Just like inches are grouped into feet or seconds into minutes, beats are grouped into units called MEASURES.  The number of beats in a measure is the same throughout the piece.  Usually the beginning of a measure is indicated by a strong accent (several drums hitting at once, and especially the bass drum hitting).  In written music, measures are separated by vertical lines (|).  The most common numbers of beats in a measure are 4, 8, 12, 3, and 6.  The Kaki Lambe has 8 beats per measure.  When you dance or walk to the music, you usually put your foot down at the beginning of each measure.

A repeated drum pattern is called a CYCLE.  The number of beats in a cycle is always divisible by the number of beats in a measure--that is, a cycle is a whole number of measures.  The cycle in Kaki Lambe is 16 beats long, which is exactly 2 measures.  Repeat signs ( ``|:'' and ``:|'' ) are used to bracket cycles.