“The first few #1 hits of 1975 were so overwhelmingly bland and narcotized and nostalgia-driven that it’s amazing, in retrospect, that something as loud and rude and noisy as the Ohio Players’ ‘Fire’ was able to break through,” (Stereogum). “‘Fire’ is literally noisy; it opens with the roar-whine of a fire engine’s siren, something that has probably caused at least a few thousand radio-listening commuters to instinctively jerk their cars over to the sides of the road over the decades. There’s nothing remotely mellow about ‘Fire.’ There’s barely any melody, even. Instead, it’s a horny and unrelenting vamp, a funk attack of towering proportions.
… ‘Fire’ hit #1 at the dawn of the disco age, and yet it’s not a disco song at all. You could definitely dance to it, and it probably got club play, but it’s a whole different sort of groove. It’s a grimy, sweaty beast of a song. And in the context of the otherwise-antiseptic early-1975 pop charts, I can only just imagine how exciting it must’ve sounded.”
At the 1:50 mark, the iconic half-step key change hits — not least because because of the tune’s one-chord harmonic vocabulary within each of the two keys!