The music/fashion overlap's a natural one, so no big surprise that Chairlift's donning Marc Jacobs' fall line for Saks.com and the store's four-part video series "MARC BY MARC JACOBS Ready-To-Wear and Accessories Collections." (Amrit, Scott, and I are doing part two.) To launch the campaign, the Brooklyn trio played Saks Fifth Avenue's New York store on Saturday. You can take ...