Understanding the Basics

In order to understand the concept of rhythmic stratification, I felt that it was necessary to define and comprehend the elements from which it is composed.

The phrase 'rhythmic stratification' can be broken down into two ideas: that of rhythm and that of strata

Using Grove Music Online, one could understand the definition of rhythm to be:

• One of two primary parameters of musical structure.
• The description and understanding of the duration and durational patternings of musical notes.

Dictionary.com states the meaning of stratum (from stratification)as:

• ‘One of a number of layers, levels, or divisions in an organized system’.

Using these two definitions we can assume an overall meaning of rhythmic stratification to be the division or layering of durational patternings into an organized system, which effects the essential structure of a musical work.

Application of Technique

With this concept in mind, we are now able to apply it as a compositional technique to music, as many well known composers have already done. One of which, is Elliot Carter. The 1988 article The Evolution of Elliott Carter's Rhythmic Practice (Bernard, J) can be found on the JSTOR database and there is a direct link available at the conclusion of this information.

The article gives detailed descriptions of Carter's numerous works but also outlines his basic principles in applying this particular compositional technique.

Elliott Carter’s 3 approaches to rhythmic emancipation:

1. Superposition of different speeds notated in common unit e.g. In his first quartet work, Carter moves between minum=60, crotchet=180 and minum=135 multiple times over a period of just seven bars.
2. two Notated rubati played against strict time e.g. accelerando and ritardando.
3. three Unrelated levels heard simultaneously e.g. soft background heard only when louder foreground parts are silenced.

Listening Example

My strongest recommendation for a listening example would be Carter's "String Quartet 2" (1959). The composer himself describes the work saying ‘…four instruments are stratified according to their repertoire of intervals, their repertoire of rhythms and their repertoire of musical gestures.’

Again, this relates to our general definition; as we can see that there are layers of musical patterns (be they rhythms, intervals or gestures)which are organized in such a way to make up the structure of an entire piece.

• "String Quartet 2" can be obtained through the QUT Library as part of the KMB208 Listenings Complilation or through the NAXOS site on the KMB208 playlist.

Other Genres

However the popluar compositions of the contemporary art music world are not the only places where rhythmic stratification can be found. A childrens canon of Frere Jaques, for example, uses the repeated layering of a musical pattern. As each voice has its own timbre, each layer will add something unique to the structure of the piece.

Another example can actually be found outside the western genres of music altogether. Javanese gamelan music uses a form of a colotomic structure known as the lancaran cycle. This is a 12 beat cycle in which 4 instruments are each given a specific rhythmic pattern. Although the rhythms themselves are quite simple, the combined texture creates an interesting and, in my opinion, pleasing effect. The colotomic structure can also be used to describe the styles of the Japanese gagaku and the Thai piphat(Wikipedia, 2006). [http://en.wikipedia.org/wiki/Colotomic]

Conclusion

There is evidence that rhythmic stratification is a widely used compositional technique among western and eastern culture as well as modern and traditional music.

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