'Una orquesta Imaginaria' (An Imaginary Orchestra) is concerned with the development of two ideas:
1) The extension of the concept of ?orchestra? by electronic means.
2) The position and displacement of sound in space defined by a four-speaker quadraphonic system.
The first idea involves the creation of timbres, that is ?instruments? which were produced electronically or recorded ?live? and then transformed electronically. These instruments were grouped in families according to their similarities. Thus, wood-like. metal-like, skin-like and string-like families of instruments were defined before the actual composition of the piece started. Towards the end of the piece a new ?breed? of instruments is produced which synthesises the different families into one.
The second idea deals with the problem of relating the position and movement in space of the created sounds, to the structure and form of the piece. The aim was to relate the spatial position and movement of these sounds to their pitch, rhythm and timbre. In this way, a melody or rhythm would occupy a certain space or move in a particular way according to its melodic or rhythmic characteristics or shape. Conversely, a melody or rhythm would be created to match a particular type of movement which seemed necessary at a particular point in time in the piece.
Una Orquesta Imaginaria is ?imaginary?, above all, because it aspires to belong in as many cultures as it draws its material from.
The piece was composed at the Royal College of Music Electronic Studio and at the City University Electroacoustic Music Studio from 1978 to 1979.