Complex sentence: Katie teamed up with Sébastien Lefebvre (of Simple Plan) for a three song EP collaboration entitled "Christmas Etc." The two wrote and recorded the songs with Sébastien being in Montreal and Katie in Vancouver.
Split into simpler sentences: Katie teamed up with Sébastien Lefebvre (of Simple Plan) for a 3 song EP collaboration entitled "Christmas Etc". The 2 wrote and recorded the songs with Sébastien being in Montreal and Katie in Vancouver.