White noise up front, just enough brown noise underneath to keep it from feeling thin and clinical, nothing else layered in to compete for attention. It's the most straightforward preset in the whole Focus set. No rain, no wind, no rising melody, just a flat, even wash sitting behind whatever you're actually doing.
If you're new to using sound for concentration, this is the one to try first. It does what focus music is supposed to do without asking you to have an opinion about it. Good for masking a noisy apartment or open office, and because it never really changes shape, it's easy to forget it's playing at all, which for background instrumental music is usually the whole point.
Under the hood it's still generated live rather than a static audio file on a loop, which is why it can run for an entire workday without ever settling into an obviously repeating pattern.
StillTune composes endless, ever-changing music for sleep, focus and relaxation. Real melody and instruments, generated live, with no audio files. Explore more sounds.