The YouTube star, whose acoustic piano covers have received millions of views online, performed a rendition of Elton John track Rocket Man on tonight's series premiere.
Will.i.am and Danny were quit to turn around, while Jessie J and Sir Tom quickly followed.
"The reason why I turned around is because I can tell there's passion, you know where you want to go and music is the vehicle to get you there," Will said.
"Your tone is there, your range is there, you're a risk taker and that's what I look for in vocalists," Jessie added.
Danny added: "You are already the complete artist!"
"Where I come from I'm known as The Voice," Sir Tom Jones argued, "So you come on my team and we can win this."
Given the choice between all four coaches, Ben said: "I want someone that can help my voice progress, help me with my song writing and pursue the creative person I want to be.
"The boys are great but I think it's Jessie J for me!"
Watch Ben Kelly's blind audition for The voice UK below...