Xenakis - Morsima-Amorsima (1962) (with score)

Morsima-Amorsima, scored for violin, 'cello, double bass and piano, is one of a family of compositions which use the ST algorithm, a programme devised by Xenakis and then run by him on IBM-France's 7090 computer. These "stochastic" experiments were partly an attempt to escape the structural hierarchies of Western music by introducing probability theory into composition. While Xenakis has been criticised for this phase of computer-generated music in his output, as James Harley points out:

"Once the program is run through the computer, the numerical output must be transcribed into music, allowing Xenakis to apply his own judgment to the results, changing details, or reordering events, as he saw fit."

Referring to his earlier stochastic composition Achorripsis, Xenakis wrote:

"In fact, the data will appear aleatory only at the first hearing. Then, during successive rehearings the relations between the events of the sample ordained by “chance” will form a network, which will take on a definite meaning in the mind of the listener and will initiate a special “logic,” a new cohesion capable of satisfying his intellect as well as his aesthetic
sense—that is, if the artist has a certain flair."

"The “definite meaning” that the music will take on for the listener as the music becomes familiar is “satisfying” not because of the inherent characteristics of the stochastic functions and distributions, but because of the “flair” of the composer. Xenakis has endured much criticism over his application of mathematical procedures to music composition; in fact, his intent has always been to enhance artistic expression." (James Harley)

For Morsima-Amorsima Xenakis was awarded first prize in the Manos Hadzidakis competition in Athens.