The Keynotes made their first recording in April 1948, less than a month after their first broadcast. They were the back-up group to the veteran crooner Sam Browne on his Decca recording of "Heartbreaker", which became a huge hit with its cheery, driving beat. The Keynotes would remain with Decca for eight years, usually backing such top of the pops singers as Denny Dennis ("I'd Give a Million Tomorrows"), Anne Shelton ("Put Your Shoes On, Lucy"), Joy Nichols ("Dreamer's Holiday"), Joan Regan ("This Old House"), Dickie Valentine ("Cleo and Me-o"), and Dave King, the comic turned crooner ("Memories are Made of This"). They even recorded with the Johnston Brothers, which must have been tricky as Johnny Johnston not only formed but led that group, too.
The Keynotes made their first public appearance at Feldman's Swing Club in May 1948, and made their first film appearance shortly after in Melody in the Dark, a minor musical starring the rubber- necked comedian, Ben Wrigley, impressionists Carl Carlisle and Maisie Weldon, with Alan Dean singing solo. Hardly ever off the radio, they were regulars on Band Parade and Melody Time, singing along with Geraldo and his Orchestra.
Johnston made his first contact with commercial entertainment when the Keynotes sang on a Radio Luxembourg Boxing Day Special in 1948, followed later by a 26-week run supporting none other than Gracie Fields in The Wisk Half Hour. Bernard Braden, the Canadian comedian, compered, while they sang to the music of Billy Ternent and his Band. The ex-BBC man John Watt, no less, produced on behalf of Lever Brothers Soap.
By 1950, the Keynotes' composition changed again when Alan Dean left to go solo, and was replaced by Harry "Miss" King, an ex-trombonist from Geraldo's band. Joyce Frazer, who had replaced Pearl Carr, was in turn replaced by a bright young Scots lassie, Jean Campbell. Despite these many changes, the Keynotes were voted the country's top vocal group several times, but destiny in the form of rock 'n' roll would shortly cause their collapse. Meanwhile, however, they had made a handful of successful television appearances, from singing with Patricia Dare in Lady Luck to guesting on the ex-bandleader Jack Payne's series Off the Record.