The Turnaround
The path-breaking turnaround in Tadd Dameron's "Ladybird":All Dominants Version
Some charts may call for Eb7 and Db7 instead of the major-7 chords. For simplicity, let's change all but the tonic chord to dominant chords (the double bar separates the turnaround from the top - or end - of the song):Cmaj7 | A7b5 | D7b5 | G7b5 || Cmaj7.
All Major 7s Version
Cmaj7 | A7sus | D7sus | G7sus || Cmaj7
All roads still lead back to 6-2-5-1.
Relation to Giant Steps:
Let's take those first three chords and transpose them down a semitone. Well also turn the second chord into a dominant and leave the third chord as a major-7:
Bmaj7 | D7 | Gmaj7
The first three bars of Giant Steps!
Of course, we have no idea that this is what inspired Trane. The mind-blowing harmonic sequences of Giant Steps boil down to the three key centers: Gmaj, Bmaj, and Eb major, all separated by a major 3rd. In the first eight bars they cycle quickly in descending order, so the beginning of each sequence happen to map nicely onto the Lady Bird ending. This is probably coincidence. In the second eight bars the key centers cycle in ascending order. Coltrane's composition is about the symmetry of those three key centers, spaced a major third apart, and the quick sequences they generate, not favoring any one. No cigar.
Suggested:
10 Must Know I VI II V Substitutions (by Jamie Holroyd)