The legend goes that radio DJs at the time felt Paul’s track ended too abruptly; the song featured the “duh-da-da-da-duh. . . dah-dah” tune that you’ve likely knocked on a door – except for those last “duh-duh”s. The Part II record consisted of exactly those two notes.
The record was released strictly as a promotional piece, as the entire album lasts for just one second.