One night, at a previous job, the radio was tuned to an adult alternative station. A co-worker and I kept noticing unusually long gaps between tunes.
"It doesn't sound like the DJ's paying much attention," we took turns saying periodically. "There are all these long pauses between the songs."
Then, after the last song in the set ended, the DJ announced, "That was (such-and-such CD) in its entirety."
I remarked to my co-worker, "Considering both of us have worked in radio, it's puzzling that neither of us thought of that earlier."
