In Part One we discussed the essence of the Steely Dan Mu Major chord – a root position major triad with the 2nd added and voiced adjacent to the 3rd – and possible 3 note voicings on guitar. In Part Two we look at the evolution of the Mu Major concept in the music of Walter Becker and Donald Fagan, and how to apply these ideas to the guitar.
The Steely Dan Mu Major chord evolved in later albums as the music–and the West Coast Studio musicians performing it–leaned more towards a jazz interpretation of the chord changes, where dissonant intervals [major and minor 2nds], slash chords and quartal harmonies abound. Starting with Dr. Wu [from the Katy Lied album], the Mu Major concept expanded to include minor chord function as well. This approach relies on the bass player to indicate the tonality [root], as the chord voicing replaces root and/or 5th with other scale tones [tensions] to add dissonance and richness.
Home At Last, from Aja, is a good example of this. Although played on piano on the recording, these 3 note voicings are playable on guitar. The intro is a G minor root position voicing on strings 4, 3 and 2, with the 2nd degree [A] replacing the G on string 4 [can we call this G Mu Minor?]. The 2nd chord, same strings, is an F Mu Major, i.e. a root position triad with G replacing F. The other 2 intro chords are an A Mu Minor [same as G Mu Minor, 2 frets higher] and Bb Mu Major [same strings, C D F].
Following the G minor intro, the verse section [“I know this super highway, this bright familiar sun”] begins with an Ebmaj9 chord. This voicing is best described as a slash chord, Bb/Eb, i.e. a Bb major triad with an Eb in the bass. This 4 note voicing can be played on strings 5, 4, 3 and 2 [Eb Bb D F]. The bass player is playing Eb. Like the Mu major and minor chords, however, the function of these chords can change if the bass player changes the root. For example, with the bass playing a C root this becomes a Cmin11 Eb/b3, Bb/b7, D/9, F/11]. This voicing is also used in Green Earrings, from Royal Scam. Starting at bar 3 with the Bb/Eb, the voicing moves in whole steps [Ab/Db, Gb/Cb].
Green Earrings also has an example of quartal harmony, occurring during the Am7 vamp which harmonizes the 1st 8 bars of the verse. These are 3 note voicings stacked in 4ths. These voicings were explored notably by John Coltrane [McCoy Tyner’s work on Love Supreme, My Favorite Things, Transitions], Miles Davis [the quintet albums with Herbie Hancock], Bill Evans, etc. in the ’50’s and 60’s. The voicing for the Am7, played on strings 3, 2 and 1 is D G C. With the bass player sounding A this voicing sounds like Am11, but with a G in the bass it’s a Gsus4 or G11, F in the bass an F13, etc. Quartal chords are built upwards in 4ths, unlike traditional triad- based harmonies [built in 3rds]. When we invert these stacked 4ths, we end uo with mu major and mu minor- type voicings. For example, the Am11 voicing from Green Earrings, when inverted, would be G C D, and, inverted again, C D G, low to high. This creates a major 2nd dissonance between the C and D. This interval is the essential characteristic of the mu major sound.