With six weeks till his birthday, daydreaming pianist and composer Robert Street (Dudley Moore) is determined to fulfil his ambitions to find a loving wife and write a great musical before he turns thirty. Aided by his fast-talking friend Oscar (Eddie Foy Jr), Robert secures financial backing for his great opus, even though he hasn't yet figured out what it's going to be. Meanwhile, a chance for romance arrives in the form of Louise (Suzy Kendall), only problem is she's already seeing the boorish Paul (Nicky Henson) and is adamant she will never marry.
An insouciant Peter Cook once cruelly dismissed Dudley Moore as "a club-footed dwarf who can imitate Debussy." Consequently, 30 Is A Dangerous Age, Cynthia seems like Moore's attempt to prove himself outside the shadow cast by his performing partner. He devised the story, co-wrote the screenplay along with director Joseph McGrath and John Wells (who stars as the effete aristocrat who backs Robert's musical), composed and conducted the score and pretty much monopolizes the screen. The whimsy and stream of consciousness gags recall Bedazzled (1967) and are very late 1960s. As in his biggest hit, Arthur (1981), Moore is very much a man-child, still getting sweets from his mother, who washes his pyjamas and sends letters concerned that he's too young to get married.
Although this taps a very real anxiety suffered by twenty-somethings ("If you haven't made it by thirty, it's highly unlikely you ever will" - ironically, it took another ten years before Moore really found global stardom), it suffers from the formlessness that typifies Joseph McGrath's movies. The script is all double-talk and innocuous fantasies (i.e. Robert imagining himself as Beethoven, Rudolph Valentino and Fred Astaire) that strain our patience while we wait for a plot to arrive. What ranks in its favour is the now-nostalgic evocation of Swinging London in all its candy-coloured nightlife, dolly birds in miniskirts, zany pop art glory. Plus some winningly surreal interludes like the pop music fantasy with Rupert singing his heart out while Louise shimmies along with silver mod-wigged dancers, or the bizarre Celtic fairytale complete with Magic Roundabout style pantomime sets that inspires his cod-Irish musical. Animation fans should look out for a few cartoon sequences and graphic effects from Richard Williams, director of Raggedy Ann and Andy (1977).
Eddie Foy Jr. - whose own musical childhood featured in The Seven Little Foys (1955), which he also narrated - is a hoot as sidekick Oscar, prone to weird monologues and underwhelming pep talks ("At the rate you're going, all you be remembered for is the dazzling whiteness of your underwear"). Also very funny is John Bird - of Bremner, Bird and Fortune fame - as the detective hired to track down Rupert when he goes AWOL, who delivers a deadpan, Philip Marlowe style voiceover. He's one of several British television comedy actors featured in the cast, including Frank Thornton (Are You Being Served), Patricia Routledge (Keeping Up Appearances), and Clive Dunn (Dad's Army).
Moore is endearing, if less compelling than as Bedazzled's Stanley Moon, while as a writer he neglects his then-wife Suzy Kendall, leaving her little to do except simper sweetly. The film works best as a showcase for Moore's musical dexterity. His wonderful soundtrack bounces from jazz to classical music, pop and even takes in a medieval ballad.