It is Jason Mraz, actually. In this case, Straight no Chaser is adding some incredible backup and are replacing the instruments with their voices.

"I Want It That Way" is a hit song by the Backstreet Boys.
This is a background music mix by Joshua Musik.
Happy singing ya'll...

Backstreet Boys - I Want It That Way

Under the Influence

Jahrestag mit Seline :-* ♥♥♥Ich liebe dich♥♥♥

Starships - Nicki Minaj ; Cover.
Amanda Olivieri.

The Lidls x Sandro Cavazza x Avicii - Without you (Carl Marc Remix)