This classical piece is beautiful! It's Rachmaninov's Piano Concerto No.2 in C Minor, Op. 18: II. Adagio Sostenuto. The one I prefer is played by Lang Lang and the Orchestra of the Mariinsky Theatre & Valery Gergiev. I don't think it's legal to post the music here, but for those of you who have i-tunes or an equivalent, I strongly encourage you to go listen to this. It's about 12 minutes long depending on the tempo of the pianist you listen to.
I think this is the most beautiful piano concerto I've ever heard (and there are some beautiful ones out there). I'm not a huge Rach fan; I supremely prefer Brahms and Tchaikovsky, but I heard this on my roommate's (thank you Andrea) Piano by Candlelight tape (yes, tape) my fishy year in college and have been looking for it ever since.
I don't know if it conjures emotion now simply b/c I was going through a lot at that time in my life or because it's truly that beautiful (probably a little of both). I'm simply thrilled to be reunited with it. This piece, to me, feels like a musical description of the storyline of my soul. (sorry so cheesy, but it's really moving). ups and downs, peace and confusion, depth and simplicity . . . all wrapped up in one amazing creation of God. In a word ... beauty.