The best part of musical performances on Jimmy Fallon: Jimmy's increasingly awkward introductions, and when the Roots perform the song with the night's musical guest. Friday night's show offered dividends on both accounts, with the Roots backing up Keri Hilson, doing some great slow jam vamping on "Slow Dance," and Jimmy Fallon saying "she's also gorgeous" during the introduction like it's some kind of a credential. Good stuff all around.

Keri Hilson's In a Perfect World... is out now.