WATCH: Ariana Grande and Christina Aguilera Duet on The Voice

Who can sing the highest notes? Who can hold those notes for the longest? Who can do the most trills on one syllable? Here you have two of the biggest set of lungs in the industry belting it out!
Christina Aguilera was due to perform with a hologram of the late Whitney Houston but things didn't go according to plan. Pop princess Ariana Grande however was more than happy to step in and perform. Opening with her latest single 'Into You', Grande struts around the stage whilst being flocked by a parade of men. The song then transitions into Grande's hit single 'Dangerous Woman'. Emerging from a fog with an army of women behind her, Christiana Aguilera enters to perform the second verse. The pair then show The Voice what they're made of and together, it's something else altogether!