The Portsmouth Sinfonia was an English orchestra founded by a group of students at the Portsmouth School of Art in 1970. The Sinfonia was generally open to anyone and ended up drawing players who either had no musical training or, if they were musicians, chose to play an instrument that was entirely new to them.

As the years passed, the Sinfonia's musicians eventually became accustomed to and more skilled at playing their instruments, which diminished the novelty of the group. Although the group never formally disbanded, it ceased performing in 1979.

‘In the Hall of the Mountain King’ was released on ‘Plays The Popular Classics’, but for some reason the track time doesn't match.