Lady Gaga, Paparazzi (Live Acoustic) - her piano work is amazing.
She's not only one of the most extraordinarily talented vocalists performing today (cf. her work with Tony Bennett), but the young lady is also quite a talented pianist.
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…because 99% of them are from less-talented people giving their opinion on her and how she's "weird" 
For what it's worth, I think her performance was one of the greatest ever. She's one of the best vocalists I've ever seen.
For the record, said performance:
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