The child band in the Broadway musical School Of Rock enjoyed a visit from a surprise guest during rehearsals – Guns N’ Roses star Slash.

The guitarist made a surprise appearance while the pre-teen band was practising the Guns N’ Roses song Sweet Child O’ Mine.

Guns N' Roses' guitarist Slash popped up while the band were practising one of his songs
Guns N’ Roses’ guitarist Slash popped up while the band were practising one of his songs (Owen Sweeney/AP/PA)

He then joined in with young guitarist Brandon Niederauer, who seemed delighted.

Singer Bobbi MacKenzie did not notice the musician until after the song, covering her mouth in surprise.

After shaking hands with the youngsters, Slash joined them on Paradise City.

The cast of School of Rock performing at the Tony Awards
The cast of School of Rock performing at the Tony Awards (Evan Agostini/AP)

The musical stays close to the plot of the Jack Black-led 2003 film, in which a wannabe rocker enlists his pupils to form a rock group to conquer the Battle of the Bands.

Slash is touring with Guns N’ Roses.