Complex sentence: On August 11, the band played an intimate show at the Shepherds Bush Empire, London and were joined onstage by The Rolling Stones Ronnie Wood to play a cover of "All Along The Watchtower".
Split into simpler sentences: On August 11, the band played an intimate show at the Shepherds Bush Empire, London. They were joined onstage by The Rolling Stones guitarist Ronnie Wood to play a cover of "All Along The Watchtower".