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.
This track was made around a nice vinyl loop from splice the i edited. on top of that iv'e added a bass guitar, horns and other instruments.
Instrument Vinyl cut loop
Sample pack Reworked Soul Selections
Loop name rss_90_vinyl_cut_deeper_Dmin