From: GUEST,LDT - PM

"'Do you have trouble whistling a melody?.'
Yep. I even have trouble whistling! lol! (usually I get a long whistle so high only dogs can hear it.) And don't suggest humming or singing either...I can't hold a tune to save my life.
;)

I am unfortunately not naturally musical....and envy those who take to it naturally. For me its a lot of hard work and concentration."

Okay, so that might not be the right approach. However, what I first wrote still applies. The way to memorize _anything_ is frequent repetition.