Bowie, who is one of Britain's most successful songwriters, rarely gives permission for his songs to be used and has never allowed them to be used in this way before. "We could not really believe it when they gave us permission," said Deep Singh, who wrote the musical. "His people had warned us that it was very unlikely that he would be interested and that he had been asked many times before."
Singh, a former screenwriter, believes that Bowie gave consent because he emphasised that his story was not a nostalgic recreation of the 1970s but was set in the future and aimed to show the timeless relevance of Bowie's lyrics. Other recent shows featuring the hit songs from the back catalogue of bands such as Queen, Abba, and Madness have all had West End success by offering audiences a chance to wallow in memories of their youth.
http://www.guardian.co.uk/music/2011/nov/27/david-bowie-musical-heroes