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.
Cool Sound design used in the drop. Hard hitting and crispy drums combined with Virtual Riot Style heavy and glitched baseline. Added an orchestral string for even more uniqueness.
Sample pack Oversampled - Smooth Keys
Loop name Smooth_Keys_150_Piano_G#min