The term ‘extended instrumental techniques’ applies to works which involve what were once unorthodox forms of sound production and articulation on various instruments. For woodwind this includes over-blown harmonics, flutter-tonguing, slap-tongue, quarter-tone production, glissandi, alternative fingerings for varying tone colours and multiphonics on all instruments. There are also specific characteristics for individual instruments which will be discussed. For brass these extended elements include slap-tongue, flutter-tonguing, quarter-tone valve or slide positions, speaking into the tube and sometimes playing at the same time and multiphonics. The strings were more exploited than wind instruments in extended characteristics by composers in the nineteenth century. While Salvatore Sciarrino has composed works with extremes of harmonics in the twentieth century, style apart, these were equally deployed by Paganini and others in the nineteenth. After 1950 we can add the use of high natural harmonics produced at the extreme scroll-end of the fingerboard, fingered quarter-tones and playing on the tailpiece. The piano, harp and percussion take on a vast range of subtleties which constantly open new doors of imagination for the composer.

The bibliography lists several books by instrumentalists which explain extended techniques on specific instruments. They, and any other sources of information on the subject, are essential reading for a conductor. The main issue in preparing such scores is that it is not always possible to imagine the sound that will result from a prescribed notation. This is especially the case with the way in which a fine composer like Heinz Holliger notates a multiphonic for the oboe:

The instruction reads: ‘Fingering as for B natural, e-hole open’. The player will, no doubt, produce a correct reading of the resultant multiphonic, but lacks the pitch notation in the score to check if it is absolutely correct. For the conductor it is even more uncertain. While this is an anomaly in the composer’s graphics it does not detract from the imaginative artistry which informs its context in the orchestral texture. The conductor has to find a solution. Initially, there is no case for misunderstanding on the part of the instrumentalist because the sounds from all the instruments relate to breath – the Greek title of the piece. There are clear directions for conducting. All the questions relate to the notation and instructions for production of unorthodox sounds.