Someone recently rediscovered this concise and coherent analysis of how Don Fagen wrote Steely Dan’s Peg. Especially helpful is the overhead camera shot on the piano, so you can see exactly what the notes are in the piano riffs.
A couple of interesting points:
- The verse is a 12-bar blues, organized by plagal cadences on the I, IV, and V degrees.
- Peg sort of defines that breezy late 70s California sound. One shouldn’t be surprised that a lot of it depends on major 7th and 9th chords in open voicings.
- The riff can be voiced an imperfect plagal cadence, landing on a first-inversion tonic, which means the bass moves down a half-step from ^4 to^ 3. That can make a nice descending chromatic bass line when the 12-bar blues goes from V to IV – watch how the bass moves G-F#-F-E.
- The interlude discussed in the second video is similar to the verse riff, but instead of a plagal cadence, it’s a half-step descent from a major 9th (G9) to a dominant 7th (F7#9) . This 2-chord riff is repeated three times in descending whole steps. This is similar to the verse riff two ways: the bass moves down by half-steps within the riff; and the entire riff descending by half-stems mimics the V-IV from the 12-bar blues.
It’s always good to know how the classics were done.