'Flamenco' in BCN (Barcelona)

Hola :) My family and I will stay for a week in BCN ( Protected content ). We are highly interested in visiting a splendid evening with 'flamenco' or any other original (Catalonia) local entertainment evening.
We don't aim for those typical touristical ones (lots of Sangria and nothing else ...).
Anyone here who could recommend that typical just off the main street small pleasant place with great and high level performances.... if you see what I am aiming for ;) Preferable in the real centre (Ramblas and closely around)
Would love to hear from you at the spot :)