Piccolo, Oboe, Clarinet in Bb, Bassoon, Horn, Trumpet in C, Trombone, Harp, Percussion, Marimba, Glockenspiel, Slide Whistle, Bass Drum, Tom-tom, Cymbal, Bell Tree, Violin, Violin, Viola, Cello, Double Bass Dorff’s seventh commission from the Philadelphia Orchestra’s education department, A TREEFUL OF MONKEYS is a setting of the folktale also known as "Caps For Sale." Typical of Dorff’s narrated works, there is humor on the surface, and a musical curriculum in the background. The monkeys and hats go up the tree accompanied by ascending scales and melodies, and finally when all the hats cascade down the orchestra plays a beautiful cascade downward.