Before his gig at Islington's Union Chapel, we talked to cult indie hero Malcolm Middleton, formerly of the greatly missed Arab Strap, about his new solo album, Madonna and a failed bid for the Christmas number 1. Can you tell us about your new album, "Sleight of Heart"?   It was originally supposed to be a mini EP, like a four track acoustic album with two songs, "Blue Plastic Bags" and "Love Comes in Waves" and......