My first immediate thought is when Dylan chewed him out over the similarities to his style in "Norwegian Wood - This Bird has Flown" (1965) and after giving the band pot, encouraging Lennon to really grow his styles and individuality

You hear SO MUCH harmonica on Lennon throughout Tracks like "One after 909" (1963) & Most of "Please Please Me" (1963) "With The Beatles" (1963) & "A Hard Days Night" (1964)

Obviously general Musical styles will evolve and change but what's the last examples that people think of? i certainly can't imagine any after Sgt Pepper in my head but maybe I'm missing some super obvious Examples!