Rico Love was an unknown rapper when he scribbled the heartsick lyrics to Usher's soulful rock hit “Throwback.” That breakthrough made him a highly sought-after songwriter, and now his forte is R&B slow-burners built on downtempo beats, like Pleasure P's “Boyfriend #2.” He's at his best when injecting power ballad choruses into the mix, as in Keri Hilson's soaring “Energy.”