Wig maker Angela Cobbin: 'Theatre is a magical world, and working in it is a privilege'

After training as a hairdresser, a chance discovery prompted Angela Cobbin to apply for work at a costumiers wig department. Now the doyenne of theatre wig makers, she tells Nick Smurthwaite about her five-decade career, the A-list jokers she’s worked with and the time she thought Pavarotti was a stagehand