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
The main guitar and piano melodies are made by me, than I added a great violin sample what I speeded up and pitched down.
Melodic loops
Instrument Violin
Sample pack TEARDROP MOB - SNOW Drill Samples
Loop name Sexy - G#Minor - 148BPM @ALDIFEKA