Katy Perry's new 'Prism' song 'Dark Horse' is markedly different than the album's first taste, the upbeat single 'ROAR.' Sonically and lyrically, 'Dark Horse' is, well, darker. If the song sounds sort of familiar, that's because its closest relative in the Perry catalog is the 'Teenage Dream' smash 'E.T.'

Featuring an assist from rapper Juicy J in the intro and in a rapped bridge, 'Dark Horse' is comprised of Perry's voice, a piano melody, fingersnaps and an undulating hip-hop beat. Remember, 'E.T.' featured Kanye West, so Perry is following a formula that has served her well.

Lyrically, the song warns a prospective suitor to tread lightly and to proceed with caution, since her love is powerful, passionate and not to be messed with or treated carelessly. She's a goddess like Aphrodite, so treat her like it. She warns, "So you want to play with magic / You should know what you are falling for / Baby do you dare to do this / Because I'm coming at you like a dark horse." 

'Dark Horse' doesn't storm out of the gates like 'ROAR' did. It's more deliberate in making its points, and it's slower and sultrier. It's also Perry at her most urban and we're using that term incredibly loosely, but it's certainly got elements of lite hip-hop. It's more like hip-pop, especially in its production values and elements.

Juicy J delivers the best line "She'll eat your heart out like Jeffery Dahmer." He's the voice of reason, also reminding the object of Perry's affections to do right by her. Or else.

We like when Perry does sassy in a subdued way.

Listen to Katy Perry, 'Dark Horse'