Each of my symphonies is based on a set of related materials for which I can see numerous possibilities for working things out, thus leading to several different movements. Symphony No. 3 is based on a series of trichords, tetrachords and pentachords that all relate to the diminished seventh chord. There are two principal ideas, the first based on pentachords and presented in a faster tempo, and the second on tetrachords and trichords. After a slow introduction, these materials are presented in a series of sections, followed by an extensive development that combines different aspects of each principal idea and then the two together, reaching an intense climax. This is followed by a transformed recapitulation and conclusion. The instrumentation, consisting of four woodwinds, four brasses, piano and strings, allows different materials to be presented in distinct instrumental groups, and when combined, to keep the threads clear. The piano, which has several solos in the quieter moments, combines with all the other groups. Tonight's concert presents only the first movement, as the other movements had not been written when the concert was planned.