What do the grapes taste like?

Something I've always wondered; what do the actual grapes taste like? Like, what exactly does a Pinot Noir grape taste like? Or a moscato grape? What about a cabernet grape? Are they sweet? Or are they tart? I guess I'm more wondering if the grapes taste like the actual wine. I wonder if we went to a vineyard around here if we could try the actual grapes. I'm going to look into that.