This work was originally written in 1964 for two 12 year old twin brothers whom Britten met whilst working in Budapest. Each twin played the piano, and one the flute and the other the violin. A second version has been prepared for those who may not be quite so versatile as the twins for whom it was originally intended, and includes a version for four players with extra ad lib. passages for the flute and violin so they should not become bored by the long waits.