The riff: Spoken in an old-time radio announcer’s voice as a man in what looks like a recording studio is shown talking into a microphone.
The explanation: I’m not sure if “the old clock on the wall says it’s time for” is a reference to anything in particular, but the Longines Symphonette was a long-running classical music radio program. It was on multiple stations from 1943 to 1957, sponsored by the Longines watch company. Talk about pulling out a pretty obscure riff, here. The same radio program was also referenced in the They Might Be Giants song “Birdhouse in Your Soul.”
Novelty factor: I don’t think I need to tell you that I had no idea. I had to run multiple Google searches to even determine exactly what he was saying before figuring out it was “Longines Symphonette.”