A night after he sang for heavy-hitters at Harvey Weinstein and Anna Wintour’s benefit for President Obama, funnyman Jimmy Fallon was belting out more tunes in the West Village, this time at piano bar Marie’s Crisis. Spies said they saw Fallon and some pals descend into Marie’s — the subterranean song saloon popular with musical theater habitués — at about 1 a.m. Friday. Fallon, looking like a “Reservoir Dogs” character in a sharp black suit, white shirt and black tie, got behind the piano and belted out “Maybe” from “Annie,” along with the crowd, a witness reports. A rep for Fallon had no comment, either spoken or sung.