Mordents
Mordents and turns are common embellishments for Lennon [...].
— Walter Everett, The Beatles as Musicians, Vol. 1 (2001), p. 72
Many Beatles songs written by John Lennon contain mordents in the vocal melody: a note briefly ornamented by an adjacent scale degree before returning to the original note. He often places them near the ends of phrases where they're followed by a downward resolution to the tonic.
These ornaments are common in many styles of music, but they distinguish Lennon from his bandmates Paul McCartney and George Harrison, who use them much less often. Lennon himself uses them most in his R&B-inspired songs from the early '60s.
There are also conspicuous vocal mordents in "Do You Want To Know A Secret," which was sung by Harrison but written by Lennon.
References in later music
The Beach Boys
It was clear that the Beach Boys were listening to the Beatles in 1964; [...] [Brian] Wilson adopted Lennon's mordent in such songs as "Don't Worry Baby" and "You're So Good To Me."
— Walter Everett, The Beatles as Musicians, Vol. 1 (2001), p. 276
The Beatles are one of my favorite groups.
— Michelle Branch, website bio (2001)
These songs share
- The key of E minor
- Verse melodies that alternate 2̂ and 3̂ in a similar rhythmic pattern
- Lyrical reference to a gun, unusual in the work of Michelle Branch