Liza Minnelli, Gerard & Mikey's parents, and Franks mom also did back up vocals on it. (I have the box set and it gives them all credit in the back of the book.)
omg iw as actually watchign an interview about this the other day!literaly! but i dont remeber WHO it was i just remember they said she did a good job of it.if i evr come across ity again,ill make sure to post it on here <3
according to wikipedia, the additional vocals on Mama is Donna Way, Gerard and Mikey's mother. Which I guess makes sense because the song is called Mama and the one of the lines is "You, should have raised a baby girl,I could have been a better son"
