i uploaded music to youtube

[Plug Drugs]

Musical notes are based on frequency.
Sometime a few centuries ago, European musicians agreed on a system called "equal temperament" where there are 12 notes and an octave note repeats itself but in a lower or higher pitch.
"what note" sounds good followed by "what note" is based on scales. A lot of simple music like mary had a little lamb is in the chromatic scale; that is not to say the chromatic scale can't produce complex music, a lot of classical music was composed in a chromatic scale. There are the major and minor chromatic scales; the major scale sounds sort of happy and triumphant while the minor scale somehow sounds sad, depressing, and lonely.

There is the pentatonic scale which a lot of blues is played in. It consists of 5 main notes and deviations from those 5 notes played based on feeling. A lot of rock is played in the pentatonic scale. It sort of sounds like something you just feel like dancing to, but the more eccentric pentatonic guitar solos sound like their own unique feeling the guitarist came up with in the moment, to me at least.

There are a shit-ton of scales. There are crazy russian and arabic scales that are freakin insanely complex and I couldn't begin to tell you how they're played.

Music like this, however:

is played in no scale whatsoever. It is noise someone made on a computer that someone bothered recording in audacity or something then uploaded to youtube