Now that many album recording sessions involve little more than a bedroom and a laptop, it's hard not to admire the elaborate genesis of Imogen Heap's fourth solo record. Written and recorded variously in her local community garden, the Himalayas and the Chinese city of Hangzhou and featuring one deliberately unfinished track (Listening Chair) that aims to condense her life into five minutes, it often feels more like a particularly ambitious performance art project than a collection of songs. But persevere and you'll be well rewarded; its feverish, idea-glutted electropop frequently resolves into something thrilling, as when the propulsive Run-Time hits it stride.