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.
Bass recorded from a novation bass station synth
Sample pack Cymatics VYPR
Loop name Cymatics - VYPR Flute Loop Wet 34 - 150 BPM G# Min