Mary J. Blige sings 'Why' on 'American Idol'

This week's guest mentor Mary J. Blige singing "Why" next on "American Idol." She did an OK job mentoring -- they're not giving the guests as much airtime as in years past, now that Jimmy Iovine is there every week.

I did like how she reacted as a real music fan to the contestants -- like when she gasped in surprise at how good Jessica Sanchez's voice is.

Her performance tonight is fine; if you like her, you liked it. If not so much, you probably checked some NBA scores.

Agree? Disagree? Tell us in the comments below, or on Twitter using #ndidol.