Atwell attracted attention with an unscheduled appearance at the Casino Theatre, where she substituted for an ill star. She caught the eye of entrepreneur Bernard Delfont, who put her on a long-term contract. She released three discs that were well received. The third, "Jezebel", went to the top of the bestseller lists. It was her fourth disc that catapulted her to huge popularity in the UK. A complex arrangement called "Cross Hands Boogie" was released to show her virtuoso rhythmic technique, but it was the B-side, a 1900s tune written by George Botsford called "Black and White Rag", that was to become a radio standard. Atwell was championed by popular disc jockey Jack Jackson, who introduced her to Decca promotions manager Hugh Mendl. Mendl launched his career as a staff producer at Decca producing Atwell's recordings.