briantrumpet
Guru
It's massively overused these days. Been watching 'Mary J Blige at the BBC' recently. It makes you even more in awe of her and similar old school singers who don't use it and those from the past who didn't need any assistance to sound amazing.
I can honestly say that I've never once heard an out-of-tune note from Ella Fitzgerald, for instance. I genuinely think she physically was unable to sing out of tune, whilst being able to sing 'blue notes' just right (i.e. not in equal temperament).