Elizabeth is attending her husband George's funeral service, together with son Edward, daughter Patricia and 12-year-old grand-daughter Joanna. During the playing of golf-loving George's favourite sentimental record, Elizabeth has a subversive musical thought, as she thinks back to World War Two, when as a 15-year-old she played in 'The Blonde Bombshells', an all-girl dance band.

Elizabeth later meets Edward and Patricia for lunch at the Barbican Centre. After striking up a conversation with Paul, a busking guitarist, her interest in music is revived. At home, she takes her saxophone out of its dusty case and, thinking she is alone, starts to play. Joanna arrives home unexpectedly, and Elizabeth tells her about her playing in the wartime band, a secret she had even kept from her late husband.

Soon Elizabeth is regularly busking with Paul. She lets Paul have the proceeds, but he pays for the pub drinks afterwards. One day, in the bar, he passes Elizabeth a note. The sender, Patrick, enters and introduces himself. He used to play drums (complete with blonde wig, make-up and a pretty red frock) with Elizabeth and the Blonde Bombshells in the Metropolitan ballroom.

Edward and Patricia (both middle-class professionals, concerned with outward respectability) are shocked to see their mother busking for cash, and decide to check Patrick out, discovering a history of gambling and bankruptcy, and a spell in prison.

But this does not prevent Elizabeth and Patrick renewing their friendship, and he shows her his old drum kit (decorated with roses) in his basement. They visit the old ballroom, now a carpet warehouse, which stirs Elizabeth's memories of the time in her life when she felt most 'alive', and she voices the thought that it would be wonderful if the Bombshells could meet up and play again once more. Grand-daughter Joanna suggests that they could play at her school dance (she just happens to be on the school's entertainments committee).

Elizabeth and Patrick begin to trace some ex-Bombshells: Vera suffers from dementia and is in care, Evelyn is in prison, Annie is active in the Salvation Army and very devout, Betty is playing piano in a Hastings seafront hotel, Gwen is performing as a singer in a jazz club in Wolverhampton and Madeline is living in France. Determined, Patrick eventually persuades Betty and Annie to join, and secures Evelyn's bail. Encouraged by Joanna, the survivors commence rehearsals.

Evelyn finds a Christmas card from American Bombshell Dinah, who, after inheriting from a succession of weathy husbands, now lives in a Scottish castle. Patrick drives to Scotland alone, finding that, on arrival, Elizabeth is already there. While in Scotland, Patrick reveals his attraction to Elizabeth.

After dinner, Dinah, in an alcoholic haze, mentions the significance of the roses on Patrick's drum kit - a rose was added for each girl in the band he had laid. Back in 1942, this had led to the Bombshells fighting among themselves after finding out that Patrick had agreed to multiple marriages. But Patrick was soon arrested and drafted into the army after a BBC producer saw him in drag in the gentleman's toilets and reported him to the authorities for dodging the draft.

As the reunion band rehearse with Betty as leader, Dinah joins them and Madeline arrives from France with her double bass. At the school dance, the Bombshells are preceded by a retro-punk band, 'Open Wounds'. Gwen arrives at the last moment, and sings brilliantly without rehearsal, winning over the teenagers for the Bombshells.

Gwen notices that an extra rose that has been added to Patrick's drum kit. He explains that he has completed the set with Elizabeth the previous night, and they announce their intention to unite on a more permanent basis.