In a 1964 interview he said he found producing "fascinating - finding the story, the director and the cast: mixing people, you know?
"[2] Harper's first credit as producer was a Dirk Bogarde comedy, For Better, for Worse (1954) directed by J. Lee Thompson for Associated British.
[3][4] Harper teamed up with George Willoughby and made Action of the Tiger (1957) at MGM, directed by Terence Young, and Passionate Summer (1958) for Rank.
[5] Harper had a big hit with The Young Ones (1961) starring Cliff Richard and directed by Sidney J. Furie.
[6] After doing the comedy Go to Blazes (1962) he did a second film with Richard, Summer Holiday (1963), the first feature directed by Peter Yates and another hit.