No one is sure how or why this exists. Lady Gaga and Kendrick Lamar are not known to run in the same circles professionally but it seems that there was a point in time when the pair were happily working on a collaboration for Kendrick Lamar's good kid, m.A.A.d city.
The track, entitled "PARTYNAUSEOUS" is a mid-tempo piano led semi-ballad that is perfectly enjoyable and inoffensive. Gaga sings the chorus and hooks while Kendrick skilfully handles some good kid era flows. Gaga sounds subdued and almost unrecognisable on this non-starter but it's a decent track nonetheless.
The track certainly isn't revolutionary and we can see why it was left off of Kendrick's groundbreaking good kid album. That being said, you're not likely to hate it.