When I listened to Abbey Road on the 50th anniversary of its release, I also realized something about the sound effects at the beginning of "Sun King." (According to Mark Lewisohn's The Complete Beatles Recording Sessions [p. 185, the entry for 5 August 1969], these were compiled by Paul.)
One of the sounds is chirping crickets, and I think this might be a subtle reference to Buddy Holly and the Crickets, who were an influence on the Beatles. It's also worth mentioning that (although by accident) Holly's "I'm Gonna Love You Too" features the sound of a cricket at the very end.
