The iconic and much loved venue has hosted scores of professional performances and amateur events.
In the next few weeks Looking Back will feature some of the people who helped make it such a special place.
The first two pictures are of the building under construction.
It opened 0n November 26, 1973 with a performance of Shakespeare’s Twelfth Night.
The theatre cost just £165,000 to build although within a few years it was in deep financial trouble.
Thankfully it survived then, many will hope history repeats itself.
The theatre was synonomous with panto and its most famous dame was Michael Cross pictured with the then mayor Pat Nash after his final performance as the dame.
The final picture was taken at a memorial concert for Derek Killeen.
Derek was a much loved director of the Key who also set up the Key Youth Theatre in 1992.