YouTube recommended me this video on Binaural Beats. It was dreadful: the absolute worst science communication you can imagine. The level of certainty attributed to a single scientific study was disgusting. The level of certainty attributed to the interpretations of facts could only be appreciated by a cargo-cultist. But, anyway. The idea was still intriguing, even if the supposed "benefits" are likely non-existent. In addition, it allowed me to work on stereo audio programming (it's terrible, and my headphone jack sucks).

W/S - Add or remove .1 Hz to the frequency playing in the left ear.
A/D - Add or remove .1 Hz to the frequency playing in the right ear.
Up/Down - Go up or down a note. Only the diatonic scale is present. Only octaves 0 to 5 are present (B5 is at the limit of what web results tell me can be heard).
Z - Sine Wave
X - Triangular Wave
C - Square Wave
V - Saw Wave
B - Toggle 12-tone equal temperament and Pythagorean temperament
N - Add white noise
Q - Quit

The maximum beat allowed is 14 Hz.

Is it useful for anything? Probably not. But, as Psychology Today says: "most experts agree that the risk of side effects is low" (https://www.psychologytoday.com/us/basics/binaural-beats retrieved June 6, 2022).