Dustin Hoffman steps behind the camera for the first time with “Quartet,” a very British adaptation of a Ronald Harwood play about a retirement home for musicians. It’s an odd, dated choice for a directorial debut, with material that’s better suited for the theater, or an old-school BBC television comedy, than a 21st Century flick from one of Hollywood’s great talents.

A comedy starring distinguished actors in a picturesque countryside setting, the movie offers what is in every sense a refined, scrubbed-clean experience. It’s so proper you practically suffocate.

Still, there’s a lot to admire here. With more than 50 years in the film business, Maggie Smith is one of its treasures. It’s a great pleasure to watch her play soprano Jean Horton, who is reunited with members of her quartet when she reluctantly moves into the Beecham House.

The home faces closure, you see, and Cissy (Pauline Collins), Wilf (Billy Connolly) and Reg (Tom Courtneay) need Jean to join forces with them at a benefit concert to save the place. Jean has decided she’s done singing, though, and a rocky history with her ex-husband Reg only further dissuades her from signing on.

It’s a juicy part for Smith, perfectly suited to her gift for paralleling sorrow and pride. She’s matched by predictably fine performances from Collins and Connolly, who does his charming Scottish rogue thing.

Courtneay, another veteran, is an ideal foil to the star. Reg’s past despair is the tangible, emotional heart beneath the film’s refined exterior.

No movie starring these actors, plus Michael Gambon (Dumbledore in most of the “Harry Potter” flicks), could possibly be all that bad.

But “Quartet” is tepid when it wants to be sophisticated, a slow-moving, middlebrow endeavor that’s about as stimulating as a cup of cold tea.