Yeah, also I used to store the music egg in the fridge along with my normal eggs, and I think that didn't help the accuracy either. I should ask the Egg Timer app people to implement playing custom songs though, these comments have thrown me back in time where I had the same reactions you describe...

By now, you have probably conditioned yourself to associate the sound with the pleasant experience of eating the food, not unlike Pavlov's dogs.

Other way around: the egg is so-so, but every time I hear the song I'm a teenager again (not that I'm that old, but that's when I was getting to know a lot of classic rock & similar), so it makes me feel young and full of potential.

Unlike... that egg.