He remakes video games musics a cappella
A cappella is an expression of vocal music indicating that a song or part of a song, one or more voices is performed without instrumental accompaniment. "Wikipedia"
The Youtuber Smooth McGroove understands what it is by taking the classic video games with his only voice. He and his cat (and yes this is important) has over 517,003 subscribers.
You can see here a Tetris remix
And here a Sonic one
If, like me, this guy fascinates you, I invite you to go on a tour on his Youtube page here.
All his creations are available to paid download here.
And if it's a game of Tetris that you want, follow this link.