What we didn't see when we first looked at the Southern-belle bar Sassafras the other day was how it looked at night. We can now say: It's even cooler. One thing of particular note, which is new for the 1933 Group who opened it and for the neighborhood, is the stage which hosts live bands of the bluegrass and folksie ilk, the kind of music that sounds good while you're sittin' a spell on an moss-covered porch with an icy pecan mint julep in your hand. Old-timey. To see for yourself, Sassafras officially opens to the public tonight (1233 Vine St.; 323-467-2800).