People tell me that my pronunciation is good in foreign languages (except for Spanish, since I'm incapable of rolling my r's - if anyone can teach me how to do it, I will consider naming my first-born after you). But I want to clear up a common misconception - this is not due to any natural "talent" with languages. I'm extremely conscious of every sound that comes out of my mouth, and I strive for accuracy in my pronunciation. It takes effort. Constant effort =P.
Which got me thinking - I wonder if studying music when you're little is correlated with improved foreign language pronunciation. I played guitar for a couple years when I was little, and I was fairly perfectionist with respect to the music. Sometimes for assignments I had to tape record (yes, cassette tapes) myself playing some piece, and it would take me forever to capture a good enough version that I was satisfied with. Of course, little did I know that professional musicians do hundreds of takes and split their songs up into segments, later cobbling them back together into a finished product.
Anyway, I grew up with a perfectionist's ear for sound and rhythm. For example, it annoys the hell out of me how large groups of people (e.g., at a stadium) cannot clap in beat to music, and always end up ahead of the beat. The fact that they're not on beat bothers me at an almost visceral level. Another example was watching Michael Jackson's This Is It. There's a scene where they're rehearsing the opening of "The Way You Make Me Feel", and the guy playing keyboard is trying to rush through the opening at a rhythm that doesn't make sense (Michael tells him that he needs to let one of the pauses "simmer"). The way the other guy wanted it just sounded "off". Michael got it. I got it. I wish I was there to back Michael up. I felt frustrated for MJ trying to explain to the guy why it sounded better his way, but it just did. It made more sense.
Now, with languages, I try to pay attention to not just the sounds of the words, but the overall pitch progression of the sentence, and the rhythm that the words are strung together. I love the rhythm and pitch variations of Korean. It's very sing-songy. It's not a tonal language, but it just sounds weird if you speak it with the wrong pitch.
I hear a lot of people speaking with pretty poor accents, and it makes me wonder what their musical background is. Some people actually can't hear the differences between sounds. My favorite example is how Americans not hailing from the Northeast are completely incapable of distinguishing between the vowel sounds in the words "Mary", "merry", and "marry" (they're all different, people!). Is this an ability that can be learned later in life after your primary auditory neural development is done? For that matter, how does your auditory system continue to develop later in life? Can you train yourself to hear sounds that you didn't grow up hearing? I don't know the answers, but my guesses are yes, your auditory system continues to develop later in life, it's just more difficult. Yes, you can train yourself to hear sounds that you didn't grow up hearing. And yes, having a musical background (i.e., a good "ear") has a direct effect on pronunciation of foreign languages.