Not a Standard Operating Procedure, no, but it does happen. I heard the CSD say to a colleagues "let's put some music on" when we had a difficult boarding in Warsaw a few weeks ago and the captain was about to announce a LHR slot issue.

It was a much more common occurence in the past, particularly when Malcolm McLaren's and Yanni's Aria on Air was the sound of British Airways. I well recall, with some horror, it being played on approach to LHR, and though it may have been a coincidence, the captain touched down precisely on the first note of the first bar after the song's bridge. Probably a bit naff to do it now, but we are talking 1990 or thereabouts.