Brass Ensemble - Level 3 - Digital Download SKU: A0.802443 Composed by E L Jefe. Arranged by Peet du Toit. Contemporary. Score and parts. 12 pages. Peet du Toit #5718181. Published by Peet du Toit (A0.802443). Frédéric Chopin's Fantaisie-Impromptu in c♯ minor Op. posth. 66 is a solo piano composition. It was composed in 1834. I'm Always Chasing Rainbows is a popular Vaudeville song, accredited to Harry Carroll, but based on Chopin's Opus 66. Here is the original section of the Fantasie-Impromptu, followed by Carroll's interpretation thereof. This combination and progression is quite enjoyable!