I think it's great when two artists you would never dream of get together and combine songs into  a better song!  That happened in June at Motley Crue show when Cee Lo Green joined them onstage for a mashup of "Don't Go Away Mad (Just Go Away)" and his "F--k You".   The songs fit together perfectly and if that happened when they cam to SPAC, the crowd would go nuts.  Check out the video for yourselves.