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.
Selected Deep House Banger.
Key: A Minor
BPM : 122
Sample pack SIIK Sounds - SLCTD Essentials
Loop name SLCTD Atmosphere 19 Amin 126BPM