There are a lot of Lady Gaga acapella/instrumental breakdowns out there, but Monster is one of the few songs of her for which full track stems are available.
Credit to GagaDaily user digital_junkie for the leak.
Bass
Cymbals
Guitar
Kickdrum
Snare
Synths & Backing Vocals
Vocals
Artist: "Lady Gaga"
Genre: "Pop"
Album: "Monster Track Stems"
Date: "2009"
Composer: "Nick Dresti; Stefani Germanotta; Nadir Khayat"