First recorded by The Crickets (1958).
Also recorded by Bobby Vee (1963), The Trashmen (1963), Waylon Jennings (1969).
Hit version by Linda Ronstadt (US #5/UK #11/CAN #9 1977).
From the wiki: “‘It’s So Easy!'” was written by Buddy Holly and Norman Petty, and first released as a single by Holly under the moniker of his band, The Crickets. The single did not chart.
“Bobby Vee, The Trashmen (‘Surfin’ Bird’), and Waylon Jennings were among the several performers who recorded cover versions of ‘It’s So Easy!’ in the decade after its original release, before Linda Ronstadt’s Peter Asher-produced Top-5 single was released in 1977 to promote Ronstadt’s Simple Dreams album.”