1. John Martin is an American male vocalist and finalist of The Voice U.S. for season 7. 2. John Martin is a Swedish singer-songwriter best known for his collaborations with Swedish House Mafia The son of a bona fide stuntman - singer and songwriter, John Martin, was born and raised in the southern suburbs of Stockholm, Sweden in the mid eighties. He received his first guitar just as he turned thirteen and duly formed his first band, playing Nirvana covers in the absence of having any songs of their own.