30 Is a Dangerous Age, Cynthia is a 1968 British romantic comedy film directed by Joseph McGrath and starring Dudley Moore.

Plot

London jazz pianist and aspiring composer Rupert Street (Dudley Moore) is looking to have a 30th birthday to remember, marriage on the big day, but lacks a bride, and in the six weeks that remain, he has set himself the no less formidable additional target of writing a musical, all through fear of reaching that grand age having achieved nothing in life. Luck comes Rupert's way in the form of the gorgeous but taken Louise (Suzy Kendall), a fellow boarder, whose attentions he pursues with all his goofy and inept might and main. The inevitable bust-up with competing suitor Paul leaves Rupert with right arm in plaster and unable to play.