Folke Rabe

Folke Rabe (Stockholm, Sweden, 28 October 1935 - 25 September 2017) was a Swedish composer. Works include the electronic drone pieces What?? (also translated as "Was??") (1968), Basta for solo trombone (1982), Escalations for brass quintet (1988), Concerto for trombone: "All the Lonely People" (1989) featuring quotes from The Beatles' "Eleanor Rigby", and With Love No. 1 and 2 for piano (1988).

According to Robert Erickson, What?? contains "no obvious discrete changes" and "no sharply defined sections". The piece uses several drone pitches, though they are presented at a time scale where pitch change is "hardly noticed." Interference beats are highlighted (as the only apparent rhythm) and, as "an elegant touch," the microtonal pitches that produce those beats "are worked into a larger pattern of pitch relations". "All possible timbral dimensions are manipulated: spectral envelope, including harmonic and inharmonic partials; time envelope phenomena, such as beats and tremolo; micropitch changes, both fast and slow. Transformations between pitch (with timbre) → chord, chord → 'a sound', 'a sound' → pitch (with timbre) abound."