Does collecting coins in Plants vs. Zombies play a song or just random notes?

I emailed Popcap to ask, and they said the following:

There is no music to the coins, they are just all random notes. So if you are hearing music, that's pretty cool and means you have a good imagination or ear for melody.

I played the game to death, unlocking every single thing in it and I also tried to find a pattern to picking the coins up. From what I could tell, they're just different notes that link well together.