Can someone identify this sound?? (Rice Military)

I’ve been hearing this exact same tune on repeat every few minutes for a couple of hours – it sounds like creepy old playground equipment but very loud somewhere in the distance, loud enough to not be drowned out by the traffic noise from Memorial. I kept track for about 45 minutes and counted 22 occurrences, and the frequency/timing has no regular pattern. The curiosity is driving me nuts!! Wtf is it!? A bird??