This is totally from a passengers point of view, but from that I have flown on flights with both Mary J Blige and Anastacia. Mary J was lovely - genuine, chatty, and had no heirs or graces. Anastacia on the other hand... nothing could be done quick enough (food served, onboard massage etc)... not that she said a lot about it, but her assistant certainly did!! Like I say though, this is just me, and should in no way be taken to always be true to life - we all have off days after all!!