New to Me: Beneath the Surface #21

In the New to Me series, I’ll call out indicators from cryptic puzzles that I haven’t seen before and which I think are noteworthy. Today’s entry, from Kyle Dolan’s Beneath the Surface #21:

Horn tooter playing two Scott Joplin pieces back-to-back in B-flat, finally? (8)

The part I love here is the “back-to-back,” which sounds, from the surface, as if we’re talking about two consecutive pieces. Instead, it is indicating that we should take a word for [Scott Joplin pieces] and lay them in two directions. That’s a RAG, yielding B(>RAG+GAR<)+T, and both [Horn tooter] as a definition and [B-flat, finally] aptly keep the whole thing on a musical kick that’s very nice.