I'm always surprised when I notice some sound that is really compelling, but that I was totally ignoring. There's a vent behind my desk at work that periodically starts to self-resonate. I can go days without noticing, but listen to it....I'd be hard-pressed to create a rhythm that was this absorbing even with my stack of electronic gear.
("no mod" refers to "no modification"....I have a series of field recordings on the 'video' link that start with a short recording of a day to day scene and then I gradually introduce modified sounds to the mix. This is pure Heater Vent.)