Bix was a great jazz horn player in the early 20th century. The standard he's playing is "At Sundown", composed by Walter Donaldson who wrote many of the popular songs in that era.

Bix died in 1931 so I don't think he ever performed on the SSRex, but certainly the appropriate kind of music. I loved that kind of music as a kid and used to listen to it all the time on "the radio" in the 40's. I called it "old-time music" as I didn't really know what jazz was till later