Original – Fleetwood Mac

This is in 4/4 time with a binary structure. The piece starts with a very short intro of two distorted, harmonising electric guitars. Vocals follow a single hit of the snare drum and we enter section A. This section consists of a six chord pattern. Dm, Am, Dm, Gm, Dm, CM, BbM, AM, Dm. While voice sings, melodic guitar lines fill in the gaps. It seems like the guitar and singer are having a conversation. Bass guitar plays the same pattern over and over while the drums play the toms and snare. After two verses comes a remarkable guitar solo. Its remarkable because of its rhythm and melodic structure. Section B follows right after another verse. This section sees a change of rhythm, but not tempo doesn’t change. The rhythm changes to swing as the drums fully play. Dm is the chord of the B section, with guitar playing melodic phrases with vocals. This continues and the track fades to an end.

Cover version – Santana

This too is in 4/4 time with a binary structure. It starts very differently with a long intro. First, the organ specifies a motif. Then congas and percussion instruments join in along with bass and smooth distortion guitar. The intro is made up of two chords, Dm and Gm. After 20 bars a main guitar solo takes place, this is the start of section A, which has only three chords (Dm, Am, Gm) compared to the six in the original. When this is over a cowbell, timbales and an electric piano join in. Santana sings two verses and a guitar solo takes centre like the original song. A verse is sang once more then the intro is played again. A bass guitar run misleads the listener to think the song is coming to the end. As the last cymbals are struck, the percussion section takes us to section B which changes to the tonic major (DMajor) and has four chords rather than one. The chords are DM, CM, BM and AM. Section B consists of lots of guitar phrases/melodies, a drum solo and then a percussion solo. There is no singing. The end is established when the electric guitar feeds back.