Some tunes, like Nostalgia in Times Square or Killer Joe or Jordu have dominant chords a tone apart, i.e. C7, Bflat7, etc, following each other (often happens in ballads too). I can usually negotiate this without much trouble, because the scales relate so closely that improvising over them is not hard. Is there, though, a way of thinking what one is doing that makes it a bit clearer? Does one just think 'now I'm playing the dominant scale of C, then Bflat', which becomes a bit hectic at faster tempi, or is there some other way of thinking about it and about what substitutions work? Advice appreciated.