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.
Used and modified melodic sample
Sample pack Hammer Dulcimer with Max ZT
Loop name SO_HD_90_dulcimer_benitoite_Am