What's surprising about this collection is not that they did it, but that it took them so long. Windham Hill records, and the label it swallowed, Private Music, wrote at least a chapter or two on chill-out music. But they've never targeted that audience before. This double CD draws from the usual Windham Hill-Private Music suspects and creates a seamless listening experience, ambient on disc one, acoustic on disc two. Disc One: Ambient features some of the pioneers of ambient music: Mark Isham, Tangerine Dream, and Patrick O'Hearn. But most of the disc draws from the melodic, bucolic, and orchestral side with State of Grace, David Arkenstone, and even Yanni. None of them are ambient by any stretch, but they do fall into an elegant flow that's more evocative than chilled. Disc Two: Acoustic has all the Windham Hill pioneers, including George Winston, Will Ackerman, Michael Hedges, and Philip Aaberg. Together, they create a pastoral flow from solo guitars to small chamber ensembles. I wouldn't bring this disc into a chill-out room, but for elegant atmospheres and pastoral moods, Windham Hill Chill has more than enough charms. --John Diliberto