WATCH: Sondheim's Old Friends Concert Streams Free This Week

The concert, which was filmed live in London's Sondheim Theatre, will stream online starting December 31st, at 5:45 PM GMT through the BBC's iPlayer, with a television broadcast that same hour on BBC Two. 

Here is the trailer for the upcoming broadcast of Sondheim's Old Friends:

Earlier this year, world-renowned producer Cameron Mackintosh invited many of Stephen Sondheim's friends to join him in a celebration of the composer's greatest talents. The concert was filmed at the Sondheim Theatre which was recently gloriously rebuilt in Sondheim's honor (previously named Queen's theatre).

The cast appearing in the concert includes Petula Clark, Rosalie Craig, Janie Dee, Judi Dench, Daniel Evans, Michael Ball, Helena Bonham Carter, Rob Brydon, Maria Friedman, Haydn Gwynne, Bonnie Langford, Siân Phillips, Jon Robyns, Clive Rowe, Jenna Russell, Damian Lewis, Julia McKenzie, Julian Ovenden, Bernadette Peters, Imelda Staunton, Charlie Stemp, Gary Wilmot, and Michael D. Xavier.

The concert was devised and produced by Cameron Mackintosh, staged by Matthew Bourne and Maria Friedman, together with choreography by Stephen Mear. A 25-piece orchestra which is conducted by Alfonso Casado Trigo joins the cast for the concert. Musical supervision is by Stephen Brooker, musical arrangements are by Stephen Metcalfe, set design by Matt Kinley, projection designs by George Reeve, lighting by Warren Letton and sound by Mick Potter.

In his review for The Guardian, Mark Lawson said: "This was a glorious memorial service, each of the tunes a eulogy, every eulogist either a current star (Judi Dench, Bernadette Peters, Imelda Staunton, Clive Rowe) or a likely future one (the cast swelled by young actors and drama school students.) In anthology shows, as in sport, selection is central. Some of the 41 songs demanded inclusion. Friedman brings piping hot comedy and vocal clarity to Mrs Lovett’s lethal recipes, A Little Priest, from Sweeney Todd."