Mister Grumble, who’s of an age and knows everything about English Progressive Rock, had no idea this piece existed. (He attributes it to having been distracted at the time of the 1969 concert, getting out of the US Army as he did, after spending 13 months overseas.) So when I played the live recording for him for the first time on Sunday he went to the moon.

The Concerto for Group and Orchestra was composed Jon Lord, lyrics by Ian Gillan. It was first performed by Deep Purple and the RPO conducted by Malcolm Arnold on 24 September; the record came out that December. The performance at the Royal Albert Hall was the first ever combination of rock music and a complete orchestra and paved the way for other orchestral rock performances.