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.
Melodics made with Kontakt, Spire, Serum, Addictive Keys. Basses in Serum.
Instrument Guitar Loop
Sample pack Function Loops Billboard Vocals
Loop name FL_BVP_Memories_Guitar_Loop_90_A#min_Dry