More information:

Many years later, when Princess Margaret was being given an honorary degree, she cited her musical tastes as ‘catholic, ranging from Mozart to Tom Lehrer’. This name check prompted a frenzied search for anything to do with Tom Lehrer, with Decca securing British rights to Songs By Tom Lehrer and An Evening Wasted With Tom Lehrer, both of which charted.
The sales activity in turn led to touring requests and eventually Tom would perform in all four corners of the globe.
Revisited, which is in effect the material on Songs By Tom Lehrer performed live, was originally released with one half of the show recorded in Cambridge, Massachusetts and the second side recorded in Melbourne and Sydney in Australia. However, sound issues with the Australian recordings prompted a UK release that relied entirely on the American recording and a cover picture taken after a live performance at the Royal Festival Hall in London in June 1960!