In 2009, Brendon Anderegg and Koen Holtkamp created with Choral the most successful record of their career, so far. They did so by scudding four hands full of instruments through their computers, piled them up and thereby created up to thirty layers per track. Leaving out overdubs and major post-processing gave the music a more natural sound, although it tended to tilt into the unknown because of all the layering. The production process of Air Museum is another one. This time, they didn’t throw acoustic instruments into the computer, but instead the Dutchman by birth Holtkamp and his constant companion Anderegg went to the studio for the very first time and paid particular attention to the post-production. The biggest surprise: In the end, Air Museum, Mountain’s fourth LP, sounds much more electronic than its predecessor. All in all, Mountain’s musical range is a much broader one than on the previous albums. This might be strengthening the musicians’ profile but, unfortunately, it doesn’t do the album any good. Choral, with its compressed sounds pierced by acoustic guitars, not only earned the two New Yorker’s music its title »21st century folk music«, but actually did make it stick out from the masses of releases in the field of electronic-acoustic music. In contrast, on Air Museum, the focus was unfortunately put – as it’s done so often these days – on the synth as the highest source of sound and therefore it often only creates a somewhat nostalgic tone, leaning towards »kosmische Musik« and »Krautrock«.