Anyone remember Papa John Creach, who played electric violin with the Jefferson Airplane/Starship? That was psychedelic rock, of course, not strictly blues, but certainly related to blues. John was not a young man and must have had spent many years playing unamplified blues/R&B before falling in with those hippies.

On the subject of the trombone, let me recommend the excellent New Orleans band Bonerama. Very sophisticated blues/jazz/rock, with a front line of a half-dozen trombones (one of them a huge bass trombone), plus sousaphone, drums, and a lone electric guitar. Their recordings are very good, but you have to experience them live to appreciate the full physical impact of all that wind power.