I'm going to be in New York for a week or so and I figured I might go to some place known for good rock/metal live shows or just some rocker friendly club. The problem is that I am illegal by American standards, can anybody help me out?

I just checked the few places I go to in NY for metal shows, that is if you're going in the next week or so, and there is.........nothing. The nearest metal show is Cradle of Filth (gay) but they are playing with Satyricon, but that's not til late February. As far as getting into a place even though you don't live in the states I don't think it matters, just have your passport in case, especially if you're old enough to drink.

There aren't any show here right now. The good ones usually happen at B.B Kings club anyway.

I think the problem is that by American law, he is too young to drink.

That was the problem right?

He's too young to get IN.

For shows, don't they just mark your hand so you can't buy drinks? That's what they do here.

Most places are all ages or 18 to enter, 21 to drink.

There are some pubs downtown (Greenwich Village/East Village/NY University area ) in Manhattan that play rock/metal. I couple of such hang-outs I am aware are Lion's Den and Red Lion. I would advise you to get to the area and enquire about where you can find such places. The good thing is that most of the establishments would be in walking distance and you can get there quicky.
As for drinking, come places strictly insist on the ID, but a few others are quite lax. However, if you clearly look under-age I think it is going to be quite difficult.