Members of the Musicians' Union picketed the performance of Seventies-based disco review Oh! What A Night, which uses a pre-recorded backing track rather than live performances.

The union has been staging protests against the show throughout the country, claiming its decision to use pre-recorded tracks is putting musicians out of business and is disappointing audiences.

The show, which features Dinnington-based entertainer Kid Creole, is according to the MU part of a growing trend of productions which seek to cut costs by relying on recorded scores.

The union's assistant general secretary, Horace Trubridge, said a live performance should be just that – live.

"Any move to replace the live music element of a live performance with a recording devalues the product," he said.

Mr Trubridge added the show had previously used a live band – and many audience members had been shocked to discover it was no longer used.

But show producer Stuart Littlewood said the show as it had been with an orchestra had been fairly predictable.

"Recording the music gives us more room on stage for dancers and screens. Nobody is losing out but the audience get a different experience from before," he said. "We got all the musicians previously in the band to record all the music. They have been paid to play music and now they are working on another show – therefore they have been paid twice."