These guys make some good music! But does that take "musical intelligence" - or just lots of practice?

“Modest Jug Band" Buckley Dueker, Creative Commons
"Beat Boxer" Natalia Valderrama, Creative Commons
“Talented: Street Electric Violinist! – Bryson Andres” RMACMEADIAPRODUCTIONS, Creative Commons

“Rockin all over the world/ Raffi the blues kid on piano.” Raffi Arto, Creative Commons