Also remembered this about Britney's Femme Fatale:
-There wasn't a final tracklist until late February of 2011, she was still recording music in February, but the only song we know off is Big Fat Bass.
-According to an alleged Insider in Pop Justice forum, Switch You On and Antidote were part of the early 2011 tracklist but they were dropped in exchange of other tracks, including Will.i.ams. Switch You On is registered in ASCAP under Fraser T Smith and Nicole Morier, but the latter's surname name is misspelled as "Mourier" which makes me question it's legitimately. (Take the whole thing with a grain of salt)
-Darkchild worked with Britney on more songs than the ones that made the cut, one was called Push My Detonator and the other one is titled Dirty White T-Shirt, co-written by Mickey Shiloh. This information comes from a person on ATRL who claimed to have ties with someone on Darkchild'a camp but seems legitimate, as there's a song called "Detonator" registered on BMI under Jerkins' and Shiloh's names.