Final answer:
Ringo Starr drums in 'Back in the U.S.S.R.' and the Soviet version imitates The Beach Boys' vocal harmonies in 'California Girls'.
Step-by-step explanation:
In the song 'Back in the U.S.S.R.', the drums are played by Ringo Starr of The Beatles. The Soviet version of the song imitates the vocal harmonies of The Beach Boys in their song 'California Girls'.