Complex sentence: In 1959, at The 2i's Coffee Bar, he met Marty Wilde and was invited to become a member of his backing group, the Wildcats who were the warm up act on "Oh, Boy!".
Split into simpler sentences: In 1959, at The 2i's Coffee Bar, he met Marty Wilde and was invited to become a member of his backing group, the Wildcats. The Wildcats were the warm up act on "Oh, Boy!".