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.
Tech House Bass with some wobbles, Pads, Breakdowns Construction and Melodic Parts made with VST Plugins such as Nexus, Serum, Sylenth1 and many others. This one has around 50 channels and it was made with a great level of detail and a lot of groove on it.
Sample pack Toolroom - Trademark Series - Mark Knight Vol. 4
Loop name TA_MK4_SYNTH_LOOP_RHODES_STAB_125_Gm