The Wuthering Heights hitmaker made her stage comeback at London's Hammersmith Apollo on Tuesday night, 35 years after her last tour.Her 16-year-old son Bertie features in the three-hour production and Bush thanks him in the concert's programme for being the driving force behind her return.She writes: "Without my son Bertie, this would never have happened. Without his encouragement and enthusiasm, particularly in the early stages when I was very frightened to commit to pushing the 'go' button, I'm sure I would have backed out."Throughout he has been my chief consultant, my editor, my confidant. In order for him to be part of this, which has always part of the deal, he has had to work really hard in order to keep his school commitments as well as his commitments to the show."He is a very talented actor and beautiful singer, as you will witness and he brings something special to the show through his presence. Thank you Bertie. Thank you so much."Bush also made a dedication to her son during her performance on Tuesday.Her sold-out 22-date run at the venue concludes in October.