I have just found a 2-CD set  issue from 1998 of Australian recordings from the 1920s. They include several tracks of songs which Bing sang, recorded in Melbourne for the Vocalion company which was established in 1927 and ceased to exist in 1934. 'Dream house', the title song of Bing's 1932 short film, was recorded by Art Chapman and his Rex (Cabaret) Orchestra circa September 1928 and released on the Broadcast label. On the same label were 'Mississippi mud' by South African-born vocalist Netta Rodney circa November 1928 and 'Because my baby don't mean maybe now' by Harry Jacobs' Palais Pictures Orchestra with vocal by Netta Rodney circa November 1928. 'Mary' (labelled apparently as 'What are you waiting for, Mary?') was released on the Vocalion label, recorded by a visiting American band Harvey Ball and his Virginians circa April 1928. The accompanying notes state that the vocalists in the trio on the last track may have included Phil Harris who was in Melbourne at the time with another US band led by Carol Laughner (which I've seen elsewhere spelt 'Lofner'). Another Crosby connection is the inclusion of two tracks by banjo soloist Eugene Pingitore, brother of Mike Pingitore, a long-serving member of the White,man orchestra.