Recorded on Evanescence, "Last Season" features soprano and fluegel. This is a piece we've continued to play over the years with my band. You should feel free to open up the solos and vary them. I've added bass on the first solo, and continued on with any other instrument from there. You can have really any instruments play on these solos, although I do think soprano is generally best for the last solo. I tend to see that this piece should slowly build from solo to solo to create an overall arch to the piece, and soprano gives that last solo the high tessitura that makes the piece come to a strong peak.
I hope the streamed interviews we've provided will be helpful to your players and whomever is conducting this piece.