It’s all in the details when it comes to copping the rhythm figure from Jeff Beck’s “Rock My Plimsoul,” a sly retake on B.B. King’s “Rock Me Baby” (credited to “Jeffrey Rod”) from 1968’s incredible Truth album. This is actually Beck’s rhythm guitar part—his main guitar (not notated) plays along with but doesn’t exactly double the part for the first three measures before switching to lead lines halfway through bar 4 of the song’s 12-bar blues progression.
Beck’s one-bar, I-chord motif is built on a common, single-note blues lick in B, and features twin low-register roots, an octave-higher B, and the b7 (A), all played as shuffled eighth-notes during the first two beats with the b7 tied to beat three. It’s a simple riff, but it’s dripping with juicy details, from the palm-muted first beat and b7-to-octave-root grace-note hammer-on and vicious vibrato on the b7 during beats two and three, to the often varied triplet on beat four. Ex. 1a, the first lick you hear, shows the moves that remain consistent on the first three beats during repeats and transpositions to the IV (E) and V (F#) chords, plus the first in a series of variations on beat four’s triplet, played here as chromatic 4-#4-5 hammer-ons (E-E#-F#). In Ex. 1b (and the next four examples), the first two beats are identical, but here we’re adding an extra A on the and of beat three. (Beat four remains the same.)
Ex. 1c changes up beat four of the original figure with a 4-5-b7 triplet (E-F#-A) that utilizes a slide between the first two notes, while Ex. 1d recasts this move as a hammer-on and includes the extra A from Ex. 1b.