I’m going to be honest and say from the start that this review underwent a complete overhaul right at the last minute. Originally I tried to look at how fans and casual listeners would view Imogen Heap’s latest album but, as I am myself a diehard fan, that became too difficult. What I concluded in that draft was that, for the casual listener, the success of the album rests on how they deal with what is, really, a rather fractured listen. Imogen’s new protracted approach to making an album has resulted in a release that lacks the sonic or thematic cohesion that would usually draw the songs on an album together. If you’re a fan whose followed the run-up to Sparks though this probably won’t prove to be a stumbling block because you’ll know about the projects that accompanied most songs. As a soundtrack to Imogen’s adventures over the last…