The base is original from the producer (chords and melodies), but is complemented with elements that complement the song that come from samplepacks, usually, vocal chops, guitars, wobbles sections, glitch effects. It is the standard in which most of producers work, in a project you will find MIDI files made by the producer, but also melodic loops.
I've changed loop pitch and added effects on it. Sections of project are organised with color.
Sample pack Cymatics - CHAOS Beta Pack
Loop name Cymatics - High Ground - 144 BPM E Min