London songwriter Imogen Heap is better known for her skill in employing the internet to push her career than for her actual music. She's got hundreds of thousands of Twitter followers and MySpace friends (though not, inexplicably, the sales to match), but the only songs that might be familiar to non-fans are the 2007 Grammy-nominated Can't Take it In and Hide and Seek, which made it on to The OC. This beguiling third album deserves to be her breakthrough moment, though the absence of an obvious Hide and Seek-style focal point may hinder its chances. Ellipse is questing and musically inventive, using electronics as its foundation, but fleshing out the bleeps and clicks with everything from the chirp of jayhawks (on Little Bird) to an Indian flautist (Tidal). An understated vocalist, Heap sounds by turns warm and inviting and mistily detached - and her resemblance to Alanis Morissette on the track Earth cannot go unremarked. Lovely stuff.