Complex sentence: Dee has had an important working relationship with the playwright and director Alan Ayckbourn which began with Paul Todd's fringe production of "Between The Lines" for which Ayckbourn wrote song lyrics.
Split into simpler sentences: Dee has had an important working relationship with the playwright and director Alan Ayckbourn. This began with Paul Todd's fringe production of "Between The Lines" for which Ayckbourn wrote song lyrics.