But can you Play It in D [flat]

Procedures are presented that provide a method by which a player may become more secure in improvising over
less-familiar tunes in unusual keys. No serious jazz player can escape the necessity of drilling ii-V-I progressions in
all keys. When a sudden tonal shift occurs in a song, a quick analysis of its tonal centers may help to prevent
harmonic disorientation. A complete or nearly complete scale that is formed by a song's various tonal centers may
also be used as a simple device for tune memorization. Investigating the harmonic organization of tunes
sometimes reveals that the various tonal centers may not be simplistic in design.