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
It's made up from a piano and a pluck layer, I added a great vox and made some fire drums.
Melodic loops
Instrument Piano
Sample pack Cymatics - Destiny
Loop name Cymatics - Gas - 143 BPM D Min Piano