Watch Mary Poppins, Phantom and Les Misérables casts perform together on Britain's Got Talent
A special performance occurred during the finale
Watch a special medley of performances from the three casts from West End musicals.
In a series of tunes, cast members from the all-star Les Misérables concert, Disney and Cameron Mackintosh's production of Mary Poppins and Andrew Lloyd Webber's The Phantom of the Opera came together to sing numbers in front of televised audiences.
Michael Ball, Matt Lucas, Carrie Hope Fletcher, John Owen-Jones, Shan Ako, Killian Donnelly, Zizi Strallen and Charlie Stemp are among those involved, with Ball going on to announce that Les Misérables will return to the West End this Christmas for a special six-week run.
Watch the performance below: