The PTO performed primarily on toy pianos and reed organs, although they also played their own secondary instruments (White on tuba and [trombone], Hobbs on bassoon and percussion, Hill on clarinet and Shrapnel on oboe).
The PTO's soundworld was often jocular; the sight of four accomplished musicians engrossed in difficult music for toy pianos was, itself, humorous.
Restful reed-organs, tinkling toy pianos, soothing psalteries, suave swanee whistles, jolly jaw harps - NO noisy electronics!
Shrapnel became a central member in People's Liberation Music, a popular-music ensemble that included Laurie Scott Baker and Cornelius Cardew.
The PTO reformed for a day of concerts at the Conway Hall, London, in 2001, in remembrance of the twentieth anniversary of Cardew's death.