Emeli Sande

Taylor Swift is almost done with her five-night stand at London's O2 Arena -- but she's not done bringing special guests on stage!

It seems like Nas has been in a good place between last year's 'Life Is Good' -- which showed contentment not only in its title, but its lyrics too -- and spending his 40th birthday with family, friends and Hennessy. We see more of this positive mindset in his uplifting verse on the remix to Rudimental's 'Free,' which also features Scottish singer Emeli Sandé.

Jazz pianist Robert Glasper is on a roll. After dropping his abstract video for 'Calls,' he releases another fantastic song from his upcoming album, 'Black Radio 2.' The Grammy-winning artist gives us the melodic 'Somebody Else' featuring the angelic vocals of Emeli Sande.