F Bb C Ab Db Eb
F: I | | IV | V |
Ab: I | IV V
The same technique is used again to modulate back to F major in the chorus: The note F is third of the Db major chord, which is then reinterpreted as the root of the F major chord.
Ab Db Eb f Db F d F C
Ab: I | IV V | vi | IV |
F: I | vi7 | I | V
Incidentally, I've been struggling a little with a harmonic analysis of The Beatles' 'Lucy in the Sky With Diamonds', which uses this same common tone modulation but in a rather more complex manner.
The verses of 'Lucy' are in A major, the pre-choruses are in Bb major, and the choruses are in G major. Transitioning from the verse to the pre-chorus employs a series of common tone chords which eventually articulate the modulation from A major to Bb major. The note A is established the root of an A major chord, which is then sustained as the third of an f# minor, then as the fifth of a d minor, then as the third of an F major, which functions as the leading tone in the key of Bb major.
A /G f# d F/C Bb
A: I | /b7 | vi | | iv
Bb: iii | V/2 | I
On paper, this shouldn't work as well as it does in practice. As Yogi Bera once put it, "In theory, there is no difference between theory and practice. In practice, there is." And the reason why it sounds so good is that the note A is common to the chords A, f#, d, and F, providing a sense of continuity despite the adventurous and most unusual modulation.
Thursday, 28 April 2016, 7:00-8:00 p.m.
Penn Area Library, 2001 Municipal Ct, Harrison City, PA
The Beatles: Band of the Sixties
Explore the music of The Beatles in this 60-minute multimedia presentation (part history and part musical analysis) spanning the full 1960's: beginning with the band's seminal visits to Hamburg, continuing through Beatlemania, and concluding with Abbey Road. The program will be supplemented with audio clips of music and excerpts from interviews with the band members.