According to the metrical hierarchy of Lerdahl and Jackendoff son clave has a metrical complexity of 17 – 13 = 4. It is not a Euclidean rhythm but has desirable rhythmic oddity as Toussaint investigates in detail in his book “The Geometry of Musical Rhythm: What Makes a "Good" Rhythm Good?”. In this book he further researches some desirable properties of the son clave rhythm such as the fact that it is a rotation of its own shadow rhythm and has significant metrical ambiguity.
If we break the son clave pattern down into its elements we receive 16 distinct pulses meaning equally spaced points in time which are either sounded (called the onsets) or silent. There are exactly five sounded pulses which is why the son clave is categorised as a (5, 16) rhythm with 16 describing the number of pulses and 5 describing the number of onsets. The breakdown of this pattern is elementary with 16 pulses in the sense that with less than 16 equally spaced time points we would not be able to recreate the son clave pattern whereas a higher level breakdown would not be able to reproduce the clave pattern unless a multiple of 16 was used and such a detailed view would not be necessary to produce the son clave pattern i.e. no extra information would be obtained from a further breakdown. 16 equally spaced points in time are therefore the minimum number of pulses needed to produce the son clave. The question therefore arises: What is so special about the number 16 and why do humans seem to prefer this 5 onset pattern above all others?
These as well as other questions surrounding the popularity of the son clave will be discussed in detail in future posts of this series.
