Mark Christensen is a studio owner and Chief Mastering Engineer at Engine Room Audio in New York City. Christensen is currently known for mastering, producing, or mixing music in the genres of rock, pop, R&B, classical, and hip hop. Christensen has worked on hundreds of albums, and five have been nominated for Grammy Awards as of 2014, with two wins. Christensen has also mastered over thirty Billboard chart top ten hits, and around 25 of the releases have gone platinum or gold.