Complex sentence: On Saturday 25 June 2011 Elbow played the Pyramid stage at Glastonbury 2011, in a performance which music journalist Stuart Maconie described as "career-defining".
Split into simpler sentences: On Saturday 25 June 2011, Elbow played the Pyramid stage at Glastonbury 2011. Music journalist Stuart Maconie stated that this performance by Elbow was "career-defining".