Before moving to Europe she made only one record – "Doin' The New Lowdown", b/w 'Digga Digga Do", as vocalist for the Irving Mills-assembled Hotsy Totsy Gang (Brunswick 4014, 27 July 1928).
"Blackbirds of 1928" was taken to the Moulin Rouge in Paris in 1929 and it was here that Welch began her career as a cabaret singer including performances at the popular nightclub Chez Florence.
Welch was asked to return to New York, where she replaced a singer in The New Yorkers (1930–1931) and sang Cole Porter's controversial song "Love for Sale".
That year, before this show was available, Welch was given permission to perform in London in Dark Doings, in which she sang "Stormy Weather", newly written by Harold Arlen and Ted Koehler.
Welch's show-stopping performance in Nymph Errant was seen by Ivor Novello, and in 1935, he gave her a part in his show Glamorous Night, in which she stood out again singing his blues song "Far Away in Shanty Town".
During World War II, she remained in London during the Blitz, and entertained the armed forces as a member of Sir John Gielgud’s company.
Her final public appearance was in 1997 at a tribute concert for Daily Mail theatre critic Jack Tinker at the London Palladium, at the age of 93; she didn’t perform, but her attendance was announced and there was a standing ovation in her honour.
[15][16] In February 2012, writer Bonnie Greer unveiled an English Heritage blue plaque at Ovington Court in Kensington, London, where Welch lived from 1933 to 1936.