Betty Buckley has now joined the line-up to play Carlotta Campion, with Lorna Luft replacing the originally announced Jennifer Coolidge as Hattie Walker. Also newly announced are Peter Polycarpou as Buddy Plummer, opposite the previously announced Ruthie Henshall as his wife Sally Durant Plummer;  Alexander Hanson as Benjamin Stone and Christine Baranski as Phyllis Rogers Stone.

Also in the cast are Anita Dobson (Stella Deems), Anita Harris (Emily Whitman), Roy Hudd (Theodore Witman) and Russell Watson (Roscoe), Stefanie Powers (Solange Lafitte), Alistair Brammer (Young Benjamin) and Laura Pitt-Pulford (Young Phyllis), newly joined by Charlotte Page as Heidi Schiller, Amy Ellen Richardson as Young Sally and Jos Slovick as Young Buddy.

The cast is completed by Sarah Bakker, Jennifer Davison, Luke Fetherstone, CJ Field, Lucy James and Emily Warner.

According to press materials, artists perform subject to availability and the producer has the right to change casting.

The concert is directed by Craig Revel Horwood, with choreography by Andrew Wright and musical direction by Gareth Valentine, conducting the The City of London Philharmonic Orchestra.

It is produced by SilverBlue Entertainment, in association with Elliot Davis. It is presented in celebration of Stephen Sondheim's 85th birthday.

To book tickets, contact the box office on 020 7589 8212 or visit www.royalalberthall.com.