The one thing more dangerous than the “supergroup” is the “super star collaboration.” We’ve seen a lot of them lately, and for every great one like Bjork & The Dirty Projectors or Kimya Dawson & Aesop Rock, there are 100 Jay-Z & R. Kelly’s floating out there. On a warm Thursday Night, I ventured to the Tenderloin to see which side of the coin this Thao & Mirah project fell on.