It's always a show-going ideal to catch an artist in that weird magic hour where they are bigger than the rooms they are playing. Here you go. Earlier this summer, Merril Garbus had several thousand people dipping and swaying to her sensuous grooves in the less-than-cozy confines of Pier 54. Which is to say that a dimly lit club show might devolve into widespread heavy petting. Some jubilant hopping too, probably. Heavy petting and moderate hopping.