It features the KHJ Radio performers singing Christmas songs. Radio Days provided this explanation:
"In 1929, Los Angeles radio station, KHJ, was owned and operated by Cadillac dealer, Don Lee. As a Christmas gift to his staff, he provided a specially-prepared Brunswick disc which featured various KHJ performers singing Christmas songs as a part of the disc. This file is a clip - a little over 4 minutes of that recording and provides some nice Christmas background reminiscent of the times."
Listen: Hear this historic radio audio.