Many years ago on British TV there was a musical variety show called the Old Grey Whistle Test. It got its name from when the show would get a first copy of an album. If, after hearing the album a few times, the doormen in the facility (who wore grey suits and were thus referred to as "The Old Greys") could be heard whistling tunes from the record, it was said to have passed the Old Grey Whistle Test.
I bring forth this obscure bit of musical trivia because I am my old "Old Grey". If, after hearing a tune once or twice, I get it stuck in my head and whistle or hum it, it has passed my own Old Grey Whistle Test.