Music is seriously like some cheat code in the 'game' of girl-getting. It's not God Mode, but it's damn well close to unlimited ammo/cash.

The only girl I know who wasn't impressed by musical ability in a guy was one who was burned badly by a guitar player in a previous relationship.

Everyone else goes weak in the knees for a guy who can play some music. Extra points if its the piano, guitar, violin.

No other skill (maybe except lovemaking skills) comes close.