Spanish/latin/mexican Music

Hi, I'm new here. I'm wanting to do something nice for a friend of mine, and write a 'dedication' of sorts to her through a piano piece. She's my AI for late music history here at university. She is studying for a doctorate in musicology focusing on latin american music. We studied a piece by Gottschalk (where my username comes from) called Souvenir de Porto Rico. I went to Puerto Vallarta over the holiday, and thought I might try my hand at writing something similar. I might start writing souvenirs for the places I go (I love to travel). 

However, when I was there, I didn't get that much time to study the music of the culture. So, my question to you guys is where can I find traditional mexican music online? I'm aware of composers like Golijov who are "classical" and blend latin idioms into the music. But, I kind of want to hear the source material.

Thanks!