Paul,
Slightly off topic, but I used to work with a Line Mechanic that used to whistle all the time out on jobs.
Being an older guy he used to whistle some quite decent tunes.
But, if you were really unlucky and worked with him on a bad day, he'd whistle the same song over and over and it would nearly drive you insane, especially if you were in the same Bucket as him for 8 hours.
We were doing a Live Glove and Barrier job one day and were due to make some live connections and the whistling was going on.
I reached around and grabbed one of the blanket clips and shoved it on his lips!.
Sure, I killed the music, but I hate distractions when I'm trying to concentrate.
Other side of the coin, I've never been able to sing, without scaring nearby animals and children.
I keep the music in my head, it plays continuously.