I'm Sorry I Haven't a Clue down opportunities to work on it as he preferred to remain a listener. The official, authorised history of the show and ISIRTA, "The Clue Bible" by Jem Roberts, was published by Preface Publishing in October 2009. Humphrey Lyttelton, primarily known as a jazz trumpeter and bandleader, was invited to be chairman because of the role played by improvisation in both comedy and jazz music. In the first series Lyttelton shared the role of chairman with Barry Cryer but he made it his own (especially once Cryer replaced Cleese as a regular panellist) and continued as chairman until his death on
I'm Sorry I Haven't a Clue new series rotating with the other Monday night comedy staples such as "The Unbelievable Truth", "The Museum Of Curiosity" and "Just a Minute". Excluding compilations and repeats, this totals 481 episodes, (excluding series 70). Some early episodes of the series, including the first, were wiped in the late 1970s. Following the BBC's Treasure Hunt appeal for missing material in 2002, several shows were recovered from off-air recordings made by listeners. In 2007, "I'm Sorry I Haven't a Clue: The Official Stage Tour" visited 9 locations across England. While the broadcast shows are recorded on location, this was the first ISIHAC