You'll Be Back from Lin-Manual Miranda's musical Hamilton (released October 16, 2015) is heavily influenced by several Sixties' pop songs including The Beach Boys' God Only Knows (released July 11, 1966), The Beatles' Penny Lane (released February 13, 1967), and the Turtles' Happy Together (released February 14, 1967). You'll Be Back borrows the staccato quarter note keyboard (harpsichord) part from God Only Knows, as well as the Wrecking Crew's muted bass line and bouncy drum groove (present in the Beach Boys' California Girls as well). You'll Be Back's glee club "da da da" vocals in the chorus are also similar to God Only Know's middle section vocals, and Happy Together's "ba ba ba" vocals, while YBB's guitar part (around 3:00) and pizzicato strings are similar to Penny Lane.
The chorus to Britney Spears and Iggy Azalea's Pretty Girls is reminiscent of the chorus to Nu Shooz 80's hit I Can't Wait (released February 1986), in terms of production/arrangement (synth sounds, bass line, claps/snaps on two and four, and tempo). In addition, the double-tracked (or Antares' effected) lead vocal is similar to Gwen Stefani's lead vocal sound in Hollaback Girl