On: Why does FM sound better than AM?

[t-3]

AM does use the frequency, it just doesn't need as much and uses it differently than FM. If it was all at a single frequency, there just be a single tone getting louder and softer.

[ndndjdjdn → t-3]

Thanks. I just learned that doing a rabbit hole about sidebands! Still getting my head around it.

[YZF → ndndjdjdn]

Once you change the amplitude of a sine wave (modulate it) it's no longer a side wave. It spreads in the frequency domain. Take the fourier transform of that and you can see the frequency components.