PHOTO: First Look - FRIENDS Cast Reunite at Tribute to James Burrows

Actor Johnny Galecki turned to Instagram to share a photo of the casts of his show, THE BIG BANG THEORY and NBC's FRIENDS (minus Matthew Perry) during the tribute to legendary director James Burrows. Check it out at left!

The casts of several of the most iconic comedy series of all time will be participating in NBC's special MUST SEE TV: A TRIBUTE TO JAMES BURROWS which will air Sunday, Feb. 21 from 9-11 p.m. ET/PT.

Burrows is recognized as TV's most accomplished comedy director. Burrows made his TV sitcom directing debut with a 1974 episode of "The Mary Tyler Moore Show." He is probably best known for his work on "Taxi," "Cheers," "Frasier" and "Will & Grace," which collectively earned him 10 Emmy Awards and four DGA Awards. He directed the pilots for all four series as well as for such other long-running comedies as "Friends," "The Big Bang Theory," "Two and a Half Men" and "Mike & Molly."

The Feb. 21 special will celebrate Burrows' 1,000th episode with his new NBC comedy "Crowded," in which he also serves as an executive producer.