Complex sentence: In 2007 (while on a ML tour break) Crook received a phone call from famed producer Kevin Shirley, who asked Paul to play on a heavy metal record for Marya Roxx.
Split into simpler sentences: In 2007 (while on ML tour break) Paul received a phone call from famed producer Kevin Shirley. Kevin asked Paul to play on a heavy metal record for an artist named Marya Roxx.