Alex & Sierra can't be stopped! For the third week in a row, the duo claimed the Pop Clash title with their single 'Scarecrow.' This round, Alex & Sierra are facing off against Jessie J's 'Bang Bang,' which features Nicki Minaj and Ariana Grande. Which song do you think should win this week's Pop Clash?

Who can resist the infectious opening beats of Alex & Sierra's 'Scarecrow'? (Not us, that's for sure!) The bittersweet love song is only made sweeter by the duo's crystal clear vocals. This song definitely tugs at our heartstrings, especially when their voices blend together on the chorus.

'Bang Bang' brings an entirely different vibe to this week's Pop Clash matchup. Jessie J, Ariana and Nicki each bring massive charisma and attitude to the collaboration. It's bombastic, confident and a total show-stopper. We love that each lady brings something different to the song and each element is showcased at different parts of the track.

Who should win this week's Pop Clash? Vote for Alex & Sierra's 'Scarecrow' or Jessie J's 'Bang Bang' once an hour until the polls close on Aug. 18 at 3PM ET.

Watch Alex & Sierra's 'Scarecrow' Video

Listen to Jessie J's 'Bang Bang' Feat. Ariana Grande and Nicki Minaj