By day and early evening, Ted Liu's is a nice-looking Chinese restaurant, just off the brickways and ficus branches of Lafayette Centre's courtyard (at 1120 20th St. NW, where Libations used to be, in deepest Briefcase Barsville). But by late evening -- specifically, after about 9:30 Friday and Saturday nights since August -- Ted Liu's becomes a rock club. Yes. A very nice-looking rock club.

At the moment, of course, the place has more potential than patrons; this is where you come in. Go past the hand-lettered, rain-beaten sign outside ("Live Music Tonight"), up the big central stairway and the first things you'll notice are the surprisingly good acoustics and layout (it's a wide, carpeted, V-shaped room with about 150 seats facing a stage at the apex).

You may also notice other benefits to this experiment by owner Liu and booking agent Michael Mann: There's no cover, and the bands are local, original and -- more often than not -- worth hearing. Recent acts -- all of which have performed without the benefit of a raised stage or lights -- include the Choirboys, Sex On TV, Beyond Help and Age of Consent.

This Friday it's Big Secrets (formerly Very Nice Plants, who'll provide their own lights); Saturday, Bob's Revenge. Other October dates include the Red Hots, Madhatters, Austin Hart & the Flashbacks, Eubie Hayve, New Keys and Clear Vision. Call 223-5160. PUNCH LINES

Twin blurbs from the comedy front:

* Wayland Flowers and Madam, an outrageous man and his like-minded dummy, play Garvin's Laugh Inn at the Georgetown Holiday Inn (2101 Wisconsin Ave. NW) this Friday and Saturday. Two shows (8 and 11 p.m.) each night, $14 per. 342-2026.

* The Comedy Cafe (1520 K St. NW) has started a regular improv night -- every Wednesday, with the ever-facile local duo Kitchen Help, wherein Holly Santos and Joe Kelly step through some sharp and funny sketches, much of which they make up on the spot. With your help. Shows at 8:30, $3 per. 638-JOKE. -- R.P.