Just as each person is made from two parents (and therefore two genetic sources), musical compositions often are too. Yesterday, in discussing John Deacon's "You're My Best Friend", I mentioned that a song can be strongly influenced by the situation it comes from - in this case, a very experienced bassist working in a world-class rock band, receiving encouragement and feedback on his writing. Today, we'll be considering another singular song, written by another experienced bassist, in another world-class rock band: "Can't Buy Me Love" from A Hard Day's Night (1964). Paul McCartney had a lot of harmonic knowledge from the pre-rock repertoire (you can hear evidence in early songs such as "I'll Follow the Sun" and his cover version of "Till There Was You".) He also had a tremendous gift for rock and roll, both as an instrumentalist (The Beatles would not have been The Beatles without his bass-playing), vocalist (listen to "I'm Down") and writer ("I Saw Her Standing There" is a great early example). And all of it comes together on "Can't Buy Me Love", a song which mixes pop chord changes - in the opening where the title is sung twice, and the blues, by way of rock and roll - in the section that begins with "I'll buy you a diamond ring, my friend...".

The theoretical aspect of the blues is understood differently by virtually every musician who is involved with them, and one of these days, I'll share a few of my own thoughts on the subject, but one thing is for sure: certain notes and chords become available to a key that are not in other styles. In this case the key is C, and two of the "blue notes" made available are Eb and Bb, and the chords used in this section (C, F and G - it's a standard twelve-bar blues, in fact) become dominant seven chords. This gives the song two separate terrains to explore. It's comprised of two different sets of genes, I guess you could say, sort of like The Beatles, as a group, and as individuals.