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.
Free use melody downloaded from the looperman .. the whole creation process is done by me
Sample pack Looperman
Loop name Night Lovell Drake Logic GZUZ 21 Savage BlocBoy