Singing and playing both piano and accordion, she began to make a name for herself as an entertainer in London, and broadcast on radio for the first time with Jack Payne's band.
During the 1920–30s, she also contributed the contralto voice to a well-known and often broadcast singing duo called The Carroll Sisters, with Elsie Eaves (soprano).
As part of the wartime Cardiff artistic and music community Mai had known Idloes Owen, also a composer, arranger and conductor, who performed with the pre-war Lyrian Singers.
He was instrumental in providing Mai with a musical score written originally by a fellow Lyrian performer, Thomas Morgan.
[3] Successful songs written by Mai Jones included: "Blackbirds" (1924), "Wondering If You Remember" (1927), "We'll Keep a Welcome" (1940), "Nos Da/Good night" (1946) and "Rhondda Rhapsody" (1951).