Is Steptoe and Son the platonic ideal of the British sitcom? Two men trapped in eternal stasis, imprisoned by class and bound together by family ties as if by hoops of steel, never to escape: it’s what half-hour comedy should be. Posterity would seem to agree, because since the sitcom ended in 1974 the two rag and bone men have never been out of work, appearing in the cinema, on stage and radio. For 30 years they made and reran the show on Swedish television, underpinning the widely held theory that Steptoe is but a step from Strindberg.

A Chorus Line is one of the great American musicals. It opened off Broadway in 1975, rapidly barged a path to a larger Broadway house and proceeded to run for over 6,000 performances, breaking records along the way. Chicago, which opened in the same season, failed to seize the city's imagination in the same way, and had to wait till the 1990s to find an audience prepared to devour it. At the Tony Awards the musical about the foot soldiers of showbiz, the faceless dancers high-kicking in line, went on to win nine gongs, and then picked up a Pulitzer Prize.

The generation of alternative comedians who emerged around 30 years ago have long since elbowed their predecessors into the long grass and themselves become the establishment. Of no performer can that be said with more certainty than Rowan Atkinson. His rubbery physiognomy is instantly recognisable to billions, which is why he – or rather Mr Bean - was granted pride of place at the Opening Ceremony as guest artist with Sir Simon Rattle and the London Symphony Orchestra.

In 1972 John Kander and Fred Ebb were invited by Bob Fosse to a private screening of his film version of their hit stage musical, Cabaret. The movie starred their protégée, Liza Minnelli, who at only 19 had won her first Tony in Kander and Ebb’s first show, Flora the Red Menace, and for whom they would go on to write “New York, New York”. “Liza was our girl, and we cared very deeply about her. We sat there afterwards and didn’t know what to say to these people whom we liked so much. Because we just hated it.”

Michael Frayn (b 1933) has been having an annus mirabilis. The play the hapless actors of Noises Off are touring is called Nothing On. In the playwright’s case, almost everything has been on. Frayn’s best-known farce spent the first half of the year tickling ribs at the Old Vic and then in the West End. A season in Sheffield featuring his more serious plays furrowed brows while one of them - Democracy, his play about federal politics in 1970s West Germany – had a run down in London.

Rob Ashford occupies a unique perch in the Anglo-American theatre. Florida-born, raised in West Virginia and a product of Broadway, where he began as a dancer in shows including Parade, Victor/Victoria and the celebrated Lincoln Center revival of Anything Goes, he some while back crossed to the other side of the footlights to build a career as a director/choreographer that has spanned the Atlantic.

Marvin Hamlisch’s three Oscars all came in 1974. "I think now we can talk to each other as friends," he said as he accepted his third award of the night. He composed the winning song "The Way We Were" (and the film's score) for Barbara Streisand, having started out on Broadway as rehearsal pianist in Funny Girl. A wizened sage warned Hamlisch that it didn't do to win so much so young, but he paid no notice and a year later went and wrote the music for A Chorus Line, his Broadway debut.

Simon Stephens (b 1971) is the most prolific British playwright of his generation. Born and brought up in Stockport, he began writing as a student in York University and had produced seven plays before his Bluebird was produced at the Royal Court in 1998. In due course along came angry, searching, passionate statements about society and belonging with punchy titles like Motortown (2006), Pornography (2007) and Punk Rock (2009) (pictured below right).

Playwright Martin Crimp is one of British theatre’s best-kept secrets. Although his neon-lit name appears in the theatre capitals of Europe, with his work a big hit at festivals all over the continent, here he is better known to students - who love his 1997 masterpiece Attempts on Her Life - than to ordinary theatregoers. The crowds that saw the 2009 West End revival of his present-day version of Molière’s The Misanthrope will remember how Keira Knightley and Damian Lewis spoke the witty text, but would they now recall who wrote it?

There is a simple explanation to why Cardiff-born Peter Gill has never directed in his home city, despite the fact that many of his own plays are set in the Catholic, working-class Cardiff of his youth. “I’d never been asked,” states Gill matter-of-factly; “it’s just a trade; it’s not a magical world. You have to ask me to do things.”