Ben Curtis made the right decision by leaving Secret Machines in 2007. The quality of the band he'd formed with his brother had steadily been decreasing - as evidenced by their recent patchy effort - so forming School of Seven Bells with twin sisters Alejandra and Claudia Deheza proved to be a judicious move.

Apparently named after a mythical pickpocketing academy in the Andes Mountains, School of Seven Bells are an interesting prospect on several levels. It's difficult to classify many of these songs without employing the over-used words 'ethereal' and 'spacey' or mentioning Cocteau Twins, but truly, 'Alpinisms' is an album that ebbs and flows over those references like an ocean tide.

Airy harmonies, a product of the Dehezas' apparently instinctive vocal connection, float above an undercurrent of rhythm that's crunchy, offbeat and hypnotic at any given time. 'White Elephant Coat''s tribal beat and dull bass twang sounds like Joy Division fronted by Natalie Merchant, 'Chain' engages a more electronic, almost Goldfrapp-like starkness, 'Conjurr''s unsteady pop is probably the most customary arrangement here (but is no less enjoyable for it), while the waiflike, piano-embellished 'For Kalaja Mari' sounds almost like Enya - if she'd grown up in the Amazon rainforest and lived steadily on a diet of magic mushrooms.

It might sound a bit too pretentious to be true, but the trio have taken the best elements of shoegaze and ambient pop, and made something quite beautiful with this album. What's more, it gets better with every listen.