8 pm: Pop Music

Why would one of the great songwriters in pop music spend a concert singing other peoples’ songs? In Joni Mitchell’s case, it’s because those other people are Harold Arlen, Richard Rodgers, Lorenz Hart and other beacons of the pre-rock era. Backed by an orchestra, Mitchell will sing some of the standards she interprets on her latest album, “Both Sides Now,” and figures to toss in a few of her own as well.

* Joni Mitchell at the Greek Theatre, 2700 Vermont Canyon Road, Griffith Park. 8 p.m. $33.50 to $88.50. (213) 480-3232.

8 pm: Theater

Continuing a surge of plays set in Stalinist Russia is the West Coast premiere of “Bed and Sofa.” Focusing on a love triangle against the backdrop of a housing shortage, author and lyricist Laurence Klavan was inspired by a Russian silent movie from 1926. The music by Polly Pen (“Goblin Market”) won a 1996 Obie Award.

* “Bed and Sofa” at International City Theatre, Center Theatre, Long Beach Performing Arts Center, 300 E. Ocean Blvd., Long Beach. Thursdays-Saturdays, 8 p.m.; Sundays, 2 p.m. Ends June 4. $25 to $35; opening, $40 to $60. (562) 436-4610.

all day: Movies

In writer-director Michael Almereyda’s update of Shakespeare’s “Hamlet,” Ethan Hawke stars as the title character, the scion of a prominent New York family whose father, the president of the Denmark Corp., is murdered. The rest of the cast includes Diane Venora as Gertrude, Julia Stiles as Ophelia, Liev Schreiber as Laertes and Bill Murray as Polonius.

* “Hamlet,” which is rated R for some violence, opens Friday exclusively at the Westside Pavilion Cinemas, 10800 W. Pico Blvd., West Los Angeles, (310) 475-0202, Sunset 5, 8000 Sunset Blvd., Hollywood, (323) 848-3500and Edwards Town Center, 3199 Park Center Drive, Costa Mesa, (714) 751-4184.

8 pm: Theater

Hal Linden stars as a playwright in P.G. Wodehouse’s adaptation of Ferenc Molnar’s 1925 comedy, “The Play’s the Thing.” The writer and his collaborators visit an Italian villa and stage a play-within-a-play to restore a composer’s faith in his fiancee. Linden was a Tony-winning stage star before he gained fame as Barney Miller.

* “The Play’s the Thing” at El Portal Center’s Mainstage, 5269 Lankershim Blvd., North Hollywood. Tuesdays and Wednesdays, Sundays, 7 p.m.; Thursdays-Saturdays, 8 p.m.; Saturdays and Sundays, 2 p.m. Ends June 4. $35 to $42. (818) 508-4200.

6:30 pm: Pop Music

Who was that masked band, anyway? Try Slipknot, a nine-piece assault squad from Des Moines that has quickly established itself as a hard-rock force--in part with its metal/hip-hop attack, in part with its uniform of coveralls and homemade masks.

* Slipknot, with hed(pe) and Mudvayne, at the Hollywood Palladium, 6215 Sunset Blvd., Hollywood. 6:30 p.m. $25. (323) 962-7600. Also Saturday at the Glass House, 200 W. 2nd St., Pomona, 8 p.m. $26.50. (909) 469-5800).

7:30 pm: Pop Music

Interstate 10 is the longest highway in the U.S., and it’s also an irresistible metaphor for musicians, as evidenced on the new album “The I-10 Chronicles.” Several of the roots-minded artists on the record will gather at the House of Blues to lay down the rules of the road.

* Joe Ely, Bill & Bonnie Hearne, Chris Hillman, Flaco Jimenez, Charlie Musselwhite, Herb Pedersen, others at the House of Blues, 8430 Sunset Blvd., West Hollywood. 7:30 p.m. $25. (323) 848-5100.

8 pm: Dance

The Orange County Performing Arts Center commissioned a work for its annual Imagination Celebration that would help audiences understand how modern dance differs from ballet. The result is “Two Thousand Steps,” a full-evening “dance adventure” by locally based choreographer Loretta Livingston. Livingston will not be dancing herself, alas, but her choreography and company have won so many Lester Horton Dance Awards in the past that there should be plenty of compensations to enjoy--including a score by Murielle Hamilton and grand-scale costumes by Martha Ferrara. Plus, of course, those 2,000 steps.

* Loretta Livingston and Dancers in “Two Thousand Steps” at the Orange County Performing Arts Center, 600 Town Center Drive, Costa Mesa. 8 p.m. $8. (714) 740-7878.

all day: Movies

John Travolta stars as the space villain Terl in “Battlefield Earth,” based on the 1982 novel by sci-fi writer (and Church of Scientology founder) L. Ron Hubbard. The film is set in AD 3000, when human beings are an endangered species and Earth is ruled by the Psychlos, an evil alien race headed by Terl. Newcomer Barry Pepper co-stars as the resistance leader for the human race.

* “Battlefield Earth,” which is rated PG-13 for intense sci-fi action, opens Friday in general release.

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FREEBIES: As part of the Playboy Jazz Festival’s free concert series, the Los Angeles Multi-School Jazz Band, under the direction of Reggie Andrews, plays a concert for seniors at Phoenix Hall, 10950 S. Central Ave., Watts. 11 a.m.-1 p.m. (310) 449-4070.

Pianist Harold Land Jr., son of noted saxophonist Harold Land, leads his quartet with saxophonist George Harper at LACMA, 5905 Wilshire Blvd., L.A. 5:30-8:30 p.m. (323) 857-6000.