premise: Macklemore's song "Thrift Shop" was number one in America in 2013.
hypothesis: Macklemore . Macklemore and Ryan Lewis 's single `` Thrift Shop '' reached number one on the U.S. Billboard Hot 100 in 2013 . The pair won four Grammy Awards at the 2014 ceremony , including Best New Artist , Best Rap Album ( The Heist ) , Best Rap Song and Best Rap Performance ( `` Thrift Shop '' ) .