ELPIA IIA for piano and computer (1994) Duration: appr. 12 min All the sounds used in Elpia IIa have basically been produced with the piano. There are "normal" piano sounds and sounds from inside the piano, treating the strings with a plectrum, muting the strings when hitting a key etc. As "normal" piano sounds recordings of a Steinway grand piano have been used. Sometimes they appear just like that, but they have also been treated and transformed in many ways: there are different systems of tuning (micro tuning), different attack times and filter settings; sounds have been transformed by time stretching, bit conversion etc. The sounds from inside the piano have sometimes also been transformed in various ways. For Elpia IIa, either a MIDI grand piano or a grand piano with a MIDI sensor strip installed inside the piano is required. The MIDI data produced by the playing of the pianist are processed by a computer program written by the composer for the Macintosh computer, allowing up to four independent layers of processing. The computer then controls a sampler containing the sound material. Elpia IIa is in a certain way an interactive piece in which the performer reacts to the electronics. The score is a graphic notation, defining certain actions and "characters" to be carried out by the pianist in a free manner (improvisation). Nevertheless, the overall form of the piece is fixed. There are four "regions" (Region A - Region D) and several parts within each region which are defined by certain characteristic MIDI procedures and sound material. Region A features mainly procedures producing random groups applied to Steinway sounds (also Steinway sounds in micro tuning) and some sustained sounds (derived from piano sounds by time stretching). Region B mainly focusses on several kinds of repetitions, using Steinway sounds, sounds derived from Steinway sounds and - towards the end of this region - percussive sounds from inside the piano. Region C almost exclusively concentrates on sounds from inside the piano: there are all sorts of metal sounds, glissandos along or across the strings with a plectrum, resonant sounds etc. The basic MIDI procedures are synchronized notes. Region D returns to Steinway sounds and various percussive sounds from inside the piano, applying fast scales in both directions to these sounds. Each region features one of the basic categories of MIDI operations (random groups, repetitions, synchronized notes, scales), but there also appear operations from the other categories. Since the processing of the MIDI data can be done simultaneously on 4 independent layers, great complexities of musical textures can be achieved. The actions of the pianist are integrated into the electroacoustic environment, so sometimes it is impossible to tell what comes from the live piano and what from the electronics. Elpia IIa was premiered by Rainer Bürck at the Pfleghofsaal in Tübingen on November 3rd, 1994.