When they first tweeted the picture of the two of them in the studio, fans of both artists became extremely excited about what music would be created as a result of Kendrick Lamar and Lady Gaga collaborating together.  They previewed a track titled "Partynauseous" to The Source last month and many people figured that their collaboration would appear on Kendrick's upcoming album "good kid m.A.A.d. City".  However, when the tracklist was released many people were left disappointed, as the song was left off of the album.  

Hearing the cries from her fans, Lady Gaga addressed the issue on her website and assured her fans that "Parynauseous" will be released in the future.

"I apologize to the fans that this situation with Partynausous is confusing. To it clear it up I must explain this. When I collaborate with an artist i work solely with them, not with their camps or management. Its purely organic and creative. I love Kendrick dearly as a friend, but was not willing to compromise musically to the changes his team was making to my music. This is why I am not his record. I have a very specific vision as a producer and songwriter, and I always have. That song will be released at a different time, for a different project. I love you, and think you should check out his stuff because he is truly great. He's a good kid, its just sometimes a mad city."

Source: thesource.com