Scalpel . . . Clamp . . . Microphone?

It’s not unusual for surgeons to relieve tension by breaking into a tune every now and then at Chicago Hope Hospital, but the staging of full-scale production numbers has been off-limits--that is, until Wednesday, when CBS’ “Chicago Hope” airs an installment featuring dancing, singing doctors and nurses. The surrealistic episode, titled “Brain Salad Surgery,” will blend drama with 10 production numbers, choreography by Kenny Ortega of “Dirty Dancing” and cast members lip-syncing songs by the likes of Dean Martin and Helen Reddy (with the exception of returning cast member Mandy Patinkin, who will sing in his own voice). The episode is the most expensive ever produced for the series and revolves around Dr. Aaron Shutt (Adam Arkin), whose life is threatened by a dangerous brain aneurysm. Shutt lapses into a coma and dreams of the milestones of his life, complete with music. Writer-producers Dawn Prestwich and Nicole Yorkin wrote the script last March after viewing such films written by Dennis Potter as “Pennies From Heaven” and “The Singing Detective.” “We were fascinated by the use of music without dramatic structure, and we wanted to come up with some way to incorporate music without damaging the reality of the show.” The episode, they added, was not a response to the recent season premiere of NBC’s “ER,” in which the cast performed live. “This was supposed to be the final episode of last season, but it got bumped,” Prestwich said.

Testing the Box-Office Temperature

Two big question marks hit the screen Friday:

When Hollywood last heard from quirky Keanu Reeves, it was early this summer in the decidedly small, Beat-era film, “The Last Time I Committed Suicide.” Opening about the same time was “Speed 2,” which Reeves had opted out of. Now, Reeves continues his cat-and-mouse game with mainstream success in “Devil’s Advocate,” in which he plays an ambitious attorney who joins a powerful firm headed by an evil boss (Al Pacino). In a sense, the story represents Reeves’ alternating vision of Hollywood: heaven or hell? Only the box office knows for sure.

Meanwhile, the latest TV star to test the big screen is David Duchovny, who plays a wisecracking surgeon caught up with underworld wise guys in “Playing God.” Can he transfer his “X-Files” popularity to celluloid? Or will he be the next George Clooney (e.g., “The Peacemaker”)? Expectations aren’t as high for Duchovny’s movie, but, you know Hollywood--it can be hellish.

A Comeback for the Neo-Punksters?

Have Green Day’s salad days come and gone? That’s what retailers are asking themselves in advance of Tuesday’s release of the Berkeley trio’s third Reprise album, “Nimrod.” Green Day helped spark a punk rock resurgence with its blockbuster 1994 album, “Dookie,” which stayed on the Billboard Top 200 chart for more than two years and sold 6.2 million copies. But the 1995 follow-up, “Insomniac,” failed to build on the momentum of “Dookie,” selling about 1.6 million copies and leaving some in the industry wary about the group’s potential. One positive sign: The new album’s first single, “Hitchin’ a Ride,” has started strongly, climbing to No. 6 on Billboard’s Modern Rock Tracks airplay chart after six weeks. “It’s a real tough call,” says Gary Arnold, vice president of marketing for the Best Buy chain. “But we think this album has huge potential and that the name Green Day deserves attention. Now we need to see what the consumer tells us. It’s too close for me to call.”

--Compiled by Times Staff Writers and Contributors