The walls bleed in this immersive, Halloween-season ‘Macbeth’

Words are filled with music, especially as Shakespeare strung them together. This week’s 99-Seat Beat guide to smaller theaters includes one of the Bard’s most operatic texts — “Macbeth,” presented by Shakespeare Center of Los Angeles — as well as three musicals: “In Trousers” by Knot Free Productions, “Girlfriend” by Diversionary Theatre and a new adaptation of Neil Simon’s “Fools” by Open Fist.

‘The Tragedie of Macbeth’ by Shakespeare Center

The essentials: “Macbeth,” the tale of a nobleman-warrior who’s on top of the world until ambition pulls him down, is packed with witches, murder and ghosts. So why not present it in the theatrical equivalent of a haunted house? That’s the leap that Shakespeare Center of Los Angeles has made with its immersive “The Tragedie of Macbeth.”

Why this? In groups of no more than 60, theatergoers progress through environments designed by retired Disney Imagineer Chris Runco. Walls drip blood; daggers rain from a ceiling; an apparition speaks. Theatergoers might find themselves in a huddle of witches or sitting at a banquet. “We keep the pressure on all the way through to the end,” says adapter-director Kenn Sabberton, “which is exactly what Shakespeare does” in the writing. This is the third year of experiential, Halloween-season “Macbeths.” Sabberton, involved in the last two, is working toward the most integrated version yet, unfolding in a brisk 90 minutes.

Details: Shakespeare Center, 1238 W. 1st St., downtown L.A. 7:30 and 9:30 p.m. Saturdays-Sundays through Nov. 2; 3 and 5 p.m. Nov. 3. $49. shakespearecenter.org

‘In Trousers’ by Knot Free

The essentials: Marvin — the nervous, overly analytical, snarky (yet somehow lovable) emotional wreck you know from “Falsettos” — has an origin story. In “In Trousers,” he relives formative experiences with the women in his life. These 90 minutes of jumpy, anxious songs are a sort of apologia to them (although in Marvin’s usual self-aggrandizing way) for all the ways things went wrong because he wasn’t being honest with them, or himself, about who he was.

Why this? This piece, first seen in 1979, launched what grew to be three one-act musicals, the latter two of which were combined into “Falsettos.” Rarely seen these days, William Finn’s “In Trousers” is being revived by the new Knot Free Productions, which intends to spotlight groundbreaking works. “In Trousers” “never really got its due,” says co-producer Tal Fox. “Its hauntingly gorgeous score and bold message of self-acceptance were way ahead of their time.” A three-person band accompanies the cast of four.

Details: Knot Free at the Lounge Theatre, 6201 Santa Monica Blvd., Hollywood. 8 p.m. Fridays-Saturdays, 3 p.m. Sundays, through Nov. 3. $30. introusersla.brownpapertickets.com

‘Girlfriend’ by Diversionary Theatre

The essentials: In rural Nebraska in 1993, a graduating senior — presumed gay and ostracized — is handed a music cassette by a popular jock. That’s the beginning of a summer of self-discovery. One young man is trying to work up his nerve; the other is afraid of making a wrong move. But day by day, as they sing the tape’s high-spirited songs to each other, they learn to just be themselves.

Why this? Todd Almond built his story around songs on Matthew Sweet’s 1991 alternative-rock album “Girlfriend,” which had resonated with the playwright in his Nebraska youth. The show was warmly received at the Kirk Douglas Theatre in 2015 after its 2010 introduction in Berkeley. Now the LBGTQ Diversionary Theatre in San Diego is giving it a tender, richly resonant production with a pair of compelling actor-singers and a rocking four-member band. So much life unfolds in these 85 brief minutes.

Details: Diversionary Theatre, 4545 Park Blvd., San Diego. 7 p.m. Thursdays, 8 p.m. Fridays-Saturdays, 2 p.m. Sundays, through Oct. 20. $20-$55. (619) 220-0097, diversionary.org

‘Neil Simon’s Musical Fools’ by Open Fist

The essentials: A tutor takes a job in a Ukrainian village and falls in love with his pupil, but everything works against him: The town is under a curse that makes everyone stupid. Neil Simon’s 1981 comedy has been turned into a musical by the team behind “deLEARious”: Phil Swann and Ron West.

Why this? Open Fist presented “deLEARious” two years ago and is now staging the Simon show’s premiere. “Fools” was a notorious failure, lasting just a month on Broadway, yet amateur and school groups loved it for a while, and at least two previous musical versions have emerged. West, who cowrote the music and lyrics with Swann and also directs, says: “There is something about the town, and how they all love each other, that is really uplifting — and they just kind of stumble upon it.”

Details: Open Fist at Atwater Village Theatre, 3269 Casitas Ave. Preview 8 p.m. Friday; opens Saturday and runs 8 p.m. Saturdays and Mondays, 4 p.m. Sundays (except 7 p.m. Oct. 13), through Nov. 17. $10-$35. (323) 882-6912, openfist.org

You always can find our latest theater news and reviews at latimes.com/theater. Recent coverage includes “Gem of the Ocean” at A Noise Within, “Never Ever Land” by Theatre Unleashed, “How the Light Gets In” by Boston Court Pasadena, “The Vandal” by Chance Theater and “The Canadians” at South Coast Repertory.