Michael’s Farewell is the music heard after the end of Stockhausen’s first Licht opera, Donnerstag (1980), when, on the occasion of the work’s Milan première, five trumpet players were placed on balconies and terraces around La Scala square. Without such open-air spacing, the music’s repetitions can seem more mechanical than visionary, but this multi-tracked performance by John Wallace manages not to outstay its welcome.

The core of the disc, and its main value, comes in the works by Roger Smalley and Tim Souster (both born in 1943), who collaborated to great effect as performers while proving bracingly complementary as composers. Smalley’s Echo III (1978), for trumpet and double tape delay (five and 10 seconds respectively) is a subtle, intricate exercise in counterpoint, often delicate in sound and superbly well-shaped in form.

Souster’s The Transistor Radio of St Narcissus (1982-83) is also much concerned with contrapuntal mirroring. But its surreal title – a housing development at St Narcissus (California) reminds a character in a novel by Thomas Pynchon of the circuit board of a transistor radio – inspires music with a phenomenal sense of fun and fantasy, which has nothing of the Cage-style collage about it. Souster’s score is a virtuoso exercise in the coordination of live flugelhorn, tape and live electronics, and it derives a well-nigh mythic power from its basic, elemental images.

The disc’s producer Andrew Powell, who worked with Smalley and Souster in the 1970s, includes a recent work of his own whose eclecticism reflects his wide experience in the worlds of classical and rock music. Like all the compositions here, it provides John Wallace with ample opportunity to display his supreme technique, and the recordings (by Kirsten Cowie) skilfully synthesise their diverse sound sources.