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Chapela, Enrico: Irrational (2009) 8'
for chamber orchestra


1.1.1.bcl.1- bl/4tom-t/crash.cym; II=marimba/tamb/cowbell/2cans/2bongo/2conga/crash.cym-pft-strings

Abbreviations (PDF)


This work is available from Boosey & Hawkes for the world.

World Premiere

City University, Graduate Center, Elebash Recital Hall, New York, NY
The New Paths Chamber Ensemble / David Alan Miller

Composer's Notes

Irrational is an exploration of the properties of irrational numbers for composing music. An irrational number cannot be written as a simple fraction or ratio; the decimal goes on forever without repeating. Using this infinite stream of decimals, one can have an infinite source of new material without a repetitive pattern. By changing the base of the number to other bases different that 10, one can have any number of elements. This data can be used to determine the 4 variants of music: duration, pitch, loudness and timbre. Famous numbers as Pi, Phi (golden ratio), e (Euler’s Number) and Square Root of 2 are some irrational numbers used for this composition.

The title Irrational not only refers to the use of irrational numbers as main material to the work, but also addresses the fact that music is not meant to be a science. Music can be composed and even explained by numbers, but it only makes sense if it’s felt. As much as irrational numbers cannot be expressed as ratios, music emotions cannot be explained as numbers.

Press Quotes

"Enrico Chapela's Irrational was a perfect curtain-raiser. The piece is based on Chapela’s explorations of irrational numbers; but this was in no way indicative of a dry or cerebral surface. On the contrary, Irrational pulsates with vibrant energy. Its frequent time changes and energetic tutti pileups were deftly negotiated by New Paths. What’s more, Chapela’s music set the stage for the rest of the concert; serving as a foreshadowing of elements grappled with throughout the concert. The evening was often about music of deft negotiations – balancing massed orchestration versus delicate linear writing and intricate metric shifts with visceral ‘dancing’ rhythms." (Christian Carey,, 09 Jun 2009)


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