Where to listen blues in New York

I'll be in NY for a few days (8-12 October) and I was wondering if there are good places where to go listen some authentic blues in the city.

I've found so many things online I can't really tell which is good or which is just a "tourist trap" so I thought to ask you new yorkers.

I'm fine with entry fees or booking in advance, if I have to.

Thanks in advance