Who or what's behind "Marshmello"?

#Mellogang - a Hashtag some of you guys already know. For those who doesn't, that's how the DJ and Producer "Marshmello" Calls his Listeners.
Marshmello, some may think okey what kind of name is that? It's the Name of real powerfull Beats, well done Songs, and an artist nobody knows.

#MusicMonday IV

It's time for our new #MusicMonday.

Today we've 1 Newcomer, 1 YouTuber and a project of the human organisation #UNICEF. 

Earlier this year they'd released the song "Imagine" by John Lennon as an Cover Version with different populair artists like Katy Perry, David Guetta, Will I.AM, Bill Kaulitz and lot more.