i'm starting to wonder how much this is even true anymore. i go to the library of a respected university where i work and find a total of two books devoted to the work of iannis xenakis. the more recent, xenakis: his life and music by james harley (routledge 2004), discusses the 1962 composition bohor on two pages:
"Bohor, orignally for eight channels, is a radical exposition of these issues [the exploration of of scales of transitions between different timbres and degrees of sonic activity], being in effect a single, slowly evolving gesture lasting close to twenty-two minutes, It is, as Xenakis states [in the liner notes to a recording of the piece released in 1970 on the Nonesuch label], 'monistic with internal plurality, converging and contracting finally into the piercing angle of the end.' There are two basic textures:there is an additional paragraph on the reception of the piece, by pierre schaeffer (director of the groupe researches de musique that sponsored the composition; schaeffer hated it) and audiences who were and would've been shocked at the volume of the piece in performance.
The low sounds are heard twice (aside from the opening sonority, lasting just ten seconds, and a few other occasions at very soft dynamic levels), beginning at the 5'30" mark, and lasting about 8 minutes, reappearing after the 17'00" mark to last just 1-1/2 minutes. The other sonority continues throughout, adding layers, one by one, until there are several sounding simultaneously. The density of each one builds and subsides independently, producing an incredibly thick, constantly evolving texture that seems to have no linear trajectory. When the sustained sound drops out the first time, there is a noticeable drop in intensity and tension, but the metallic sounds build up again, leading at the end to a sublmation of all the othe rlayers to the noisiest, crashing sonority, which sharply boosts its mass and dynamic level over the final three minutes." (harley 20-21)
- A concentrated, teeming sonority, constantly in motion, ranging in timbre from bell-like sounds (filtered to muffle the resonance) to metallic rattlings, finer-grained metallic sounds closely resembling the charcoal crackles of Concret PH, and noist clashings and crashings;
- A low, sustained sound adapted from recordings of a Laotian mouth organ, the characteristic crescendo-decrescendo and breaking off for breath being preserved.
and that's it. not to knock harley, who admirably and successfully, as far as i can tell, takes on the job of surveying xenakis' fifty-year career as a composer. but compare this with the entry at columbia university's masterpieces of twentieth-century electronic music. the site features detailed analysis of sound sources and compositional structure -- to the extent that these are available -- with information and archival materials provided by the xenaxis estate. we learn that the eight tracks are apparently mirrored mixes of four disinct source materials: the laotian mouth organ (called a khen or khaen), iraqi bracelets and hindu foot bracelets, byzantine chant, and piano. (how exactly the last two source materials were used remains somewhat of a mystery.) the site has sample sound files of the khen, manuscripts schemas, graphs with amplitude and pitch graphing, and a quicktime preview of a recent video made to accompany the piece.
columbia clearly has access to materials and media that harley's print work cannot compare with; likewise he surveys xenakis' complete career. so ultimately it's not a matter of choosing one of the other, but the columbia project online is quite impressive.