In reply to blue.

Ermm don´t they appear on the video and also in her performance at the grammys? Could you imagine Mariah having Paul and those type of people in her single and performances when she was at her peak? First of all didn´t need it, not even when she went for a huge change of direction (like Rihanna seems to be going for now), but most importantly: it would have been HUGE!
And I´m talking about Mariah cause you mentioned my fave. Thing is she always needs all the help in the world to release anything, for her albums to be made, and for trying to convince part of the public she has some artistry (which she hasn´t and that´s why she needs all the help).