I've got a "single F horn" that's a conversation starter (altonium?). Outside of an old Salvation Army Band I doubt anyone uses them these days. It's like the one I started band with back in the dark ages. My original had 2 tuning slides for F or Eb switching. (Since horn music was written for Eb horn or F horn back then.) Have any of you old timers ever used these Alto Horns in your bands? They look like miniature baritones(tenor horns).