Nature and fire is the least musical pillar. There is no scale to follow, only weather: campfire, surf, rain, forest at night. Most seeds here are built from shaped noise rather than oscillators.
Campfire seeds use brown noise for the body of the fire, with randomised bandpass bursts standing in for pops and embers. Ocean seeds use pink noise with a slow LFO on the filter cutoff, so the wash rises and falls instead of sitting flat. Forest seeds add short high chirps at irregular intervals over a low wind bed.
These tracks are steady by design. Nothing in them asks for attention, which makes them useful for reading, cooking, or covering a noisy street. They are also the pillar that benefits most from a real speaker rather than a phone: the low end is where the fire and the surf live.
If you need to sleep through background noise, start with a rain or surf seed and let the timer run to eight hours.