Pretend
Pretend was written in 1952 by Lew Douglas, Cliff Parman, and Frank Levere. Nat King Cole's recording was the most successful, it reached the Billboard magazines Best Seller chart in 1953, peaking at #3. Cole later redid the song for his 1961 album The Nat King Cole Story.
Other notable recordings were made by Eileen Barten, Carl Mann, Ralph Marterie, Tab Smith, and Alvin Stardust.
Tutorial
Sheetmusic
Try a GoogleImage search. Matching the 1st measure usually suffices.