sentences:  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 members met each weekend to rehearse, bringing new pieces with them to rehearse.The music mostly reflected the composers' interests in early British experimental repetitive compositional methods, which led to the strict numerical processes called systems music.