Rap artists who rocked out with Elmo and Big Bird.
Plus J. Cole gets steamy on a Jessie Ware remix.
When you are feeling down listen to these tracks for a pick-me-up.
Nicki Minaj brings out Ariana Grande, Usher and Breezy plus more surprises.
Plus Kendrick Lamar co-signs new concert app Turnstile.
Seeing doesn't always mean believing for these music stars.