Harpo Marx (of the ‘Marx Brothers’ fame) lived at the Garden of Allah early 30s with his wife Susan. The bungalows there had notoriously thin walls. He later got a new neighbor whose hours didn’t coincide with Harpo’s and who played the piano endlessly, and who wouldn’t shut up even after Harpo banged on the wall, etc. As revenge, early one Saturday, Harpo played the first 64 bars of Rachmaninoff’s Piano Concerto #1 as loud as he could, over and over and over all day long until he heard his new neighbor scream in strangled anguish and bang around like he was packing up, slammed his door, and disappeared, never to be seen again. A lot of effort, Harpo thought, but well worth it to be rid of such a nuisance. Then somebody told Harpo that his new neighbor the piano player was Rachmaninoff himself.