Complex sentence: He co-owned a studio, Birdland, with producer Lindsay Gravina and worked in event musicals for a number of years until, in 1998 he was asked by Klaus Baumgart to create a series of musical and audiobook productions for the "Laura's Star" series.
Split into simpler sentences: He co-owned a studio, Birdland, with producer Lindsay Gravina and worked in event musicals. In 1998 he was asked by Klaus Baumgart to create a series of musical and audio-book productions for the "Laura's Star" series.