Supporting circumstantial evidence from this obituary -

By the late 1950s, Baldry was a leading figure on the Soho scene and the only regular performer at both the blues club of Alexis Korner and Cyril Davies and the folk-song sessions run by Ewan MacColl and Peggy Seeger. The policy of the irascible MacColl was that singers should perform only the music of their native country, but he made an exception for Baldry, who remained a close friend until MacColl's death in 1989.

The Guardian, Saturday July 23 2005