In one of Django's recordings of Minor Swing, not sure which one off hand, there is a phrase over E7 I don't quite understand.
It ascends like this: F G# B D F# G# B D F F# (Down beat on the first G#)
Actually, I think I just figured it out while typing this. Is it simply a mix of Fdim and E7 without the root (E)? I was stuck trying to think of what chord would include both the F and F#. Maybe there is, but I'm guessing it's simply a mix of those two arpeggios. Is that correct?