More and more, Canada's hip-hop artists are aggressively imposing themselves on the American hip-hop scene. Marco Polo arms himself with not only an impressive selection of beats, but an extensive rolodex, recruiting many of rap's entrenched veterans for his projects. Teamed up with Torae, Brooklyn's own, the duo recently released "Double Barrel" on Duck Down Records. Below is the song "Hold Up," starring Masta Ace and Duck Down labelmate Sean Price. The duo's website is http://www.myspace.com/doublebarrel08.