Music makes me cry?

It means it's beautiful, and you appreciate the beauty of it... I'm the same way, with the same instruments. Be grateful. Life without the appreciation of the arts is LAME.

You love art.

From another point of view, it's means that the composer and the musicians have done their job well. They've evoked an emotional response from their listener.

The piano moves me to tears too sometimes (have you ever seen the Holocaust film The Pianist? The piano in that just pushes me over the edge every time). The violin is so sweet sounding as well. It just makes the music so much more beautiful. Guitar can also have this sweet, sonically pleasing sound as well... like in "My Sweet Lord" by George Harrison, for instance

Okay so this is quite normal...my own theory (mixed with some professional's) is that that particular melody trigger a part of your brain that connects your emotions...
It's different for everyone...
But if you want further information you can try search "synesthesia" and "Chromesthesia" and perhaps you can find out something related to your case...
Hope this helps! ;)

Well, sometimes a certain beat/melody reminds you of a bad or sad time in your past. Your brain subconsciously absorbs certain beats and associates it with different periods of time in your life. I have also gotten sad over a certain beat/melody because I associate them with bad times in my life. Don't worry, you are not the only person you feels this way.

Music can be the same thing as the lyrics. It touches everyone's heart.

The beauty is what makes us fall in love with it and cry (: