Californian acid rockers Sleepy Sun follow up last year’s Embrace with another serving of massive, sun-blasted riffs. On Fever, however, they subvert the dynamics of ostentatious heaviosity by adding some infectious boy-girl folk pop ( ‘Ooh Boy’, ‘Rigamaroo’) and some compelling sonic curveballs that keep the listener guessing to the finish. Far from a study of hairy rock esoterica, Sleepy Sun makes light work of what could have been an exercise in ear-punishing psych.

Opener ‘Marina’ swings between desert rawk - all rattlesnakes and dust-bowl harmonica - and blissful folksiness before a total flip of script arrives in the form of swampy tribal rhythms and chanting that sounds like a New Age take on gospel. Perhaps it shouldn’t work but somehow it does.

There is something faintly Espers about the folk pop of ‘Rigamaroo’, while ‘Wild Machines’ sets a slightly hokey scene by chucking in some Ennio Morricone whistling into a sonic mêlée that includes preposterously monstrous riffage. Elsewhere there is a desert sunrise comedown (the appropriately titled ‘Acid Love’), peyote-noir (’Open Eyes’) and a hint of protest on the scattershot rhythms of ‘Freedom Line’.

Yet the highlight of the album is surely ‘Desert God’, which shimmers into view like an improbable mirage. All heavily reverbed psyche-blues, it repeats the opening track’s total wind-change with a thumping harmonica breakbeat of sorts before some delightfully squiggly guitar solos.

Fans of, say, Spiritualised and Brightback Morning Light should enjoy Fever; it may even suit fans of My Morning Jacket’s expansive early albums, albeit relocated from humid Kentucky to breezier Laurel Canyon.