Australian Music Centre | Breaking sound barriers

The "impromobile" is a concept I initially developed with my piano work, Three Improvisatory Mobiles for piano (1981) that was published in Jeff Pressing's anthology, Compositions for Improvisers (La Trobe University Press, 1994). The idea of a mobile in experimental music is a series of floating musical fragments that can be played in any order, a musical equivalent of Alexander Calder's moving sculptural forms. I extended this idea to allow for the performer to improvise on the fragments, taking the musical idea contained in each fragment as a motif for development.
Three Impromobiles is a series of improvisatory mobiles conceived in much the same way as my earlier work.
"Impromobile I"
This piece is a series of fragments composed using Messiaen's "Second Mode of Limited Transposition", a scale that alternates minor seconds and major seconds. It is intended that the improviser would develop the fragments using only the eight notes available in this particular transposition of the scale (C, D flat, E flat, E, F sharp, G, A, B flat). Simultaneously combining and developing the musical materials of two or more fragments is another performance option.
"Impromobile II"
This piece consists of a series of four or five note chords each of which has a common tone, D sharp (or E flat). The lowest tone of all the chords is either a B natural, C natural or D flat (or C sharp). It is thus possible to make a smooth transition from any one chord to any other chord. The piece could be played meditatively just as a chord progression. Alternatively the chords could be used as the basis for improvising melodically: that is, sounding a series of the chords and interpolating melodic improvisations over them. Another possibility is for one musician to play a chord sequence while another player (either of a chordal or a single-line instrument) improvises over this progression. The improvising musician would not necessarily know what the chords were except through aural recognition.
"Impromobile III"
This piece is a mobile of pentatonic scales, each of which includes the tones C and E. With these common tones it is possible to improvise on a scale and then change to any other of the scales with a relatively smooth transition. I had in mind a kind of minimalist, trance-like approach in the improvisation, although I do not wish to be prescriptive. The choice of C and E as common tones is a
reference to Terry Riley's In C.
Three Impromobiles may be adapted for any other chordal instrument, single-line instrument or any combination of chordal and singleline instruments.