I wasn't expecting this to be padded or anything, but when I say thin I mean THIN. My fabric hasn't ripped yet, but I don't know how long it will hold up. I wore a black sports bra under the light blue top, which looked pretty from behind (although they didn't completely align). I wouldn't get this in a light color if you're worried about showing through.
If it's for a one time performance, go ahead and get it, but I'm not so sure about the long run.
After 30 minutes of wearing this top, there is already a hole where the lace meets the front fabric. I am a 38C, and I purchased a Large. What I thought was "comfortably snug" when I first put it on must have been "too tight" for the fabric, since it has already torn. If this came in an XL, I would have ordered that, but I'm not sure the lace would hold up either way.