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.
Process note
Used and modified guitar sample
Melodic loops
Instrument GUITAR MELODY
Sample pack Julez Jadon Saucey Guitars Vol. 4
Loop name Guitar_Loop_Mailbox_01_179_Dmin