Trembling Bells: The Sovereign Self (Tin Angel)

British psych is alive and very much kicking in Trembling Bells – the Glasgow-based quintet featuring percussionist and principal songwriter Alex Neilson, multi-instrumentalist vocalist Lavinia Blackwell (think Grace Slick meets Sandy Denny), Mike Hastings (guitar), Alasdair C Mitchell (guitar, glockenspiel) and Simon Shaw (bass).

The addition of second guitarist Mitchell has pushed this fifth album towards wilder country than that traversed by 2012's collaboration with Bonnie 'Prince' Billy, The Marble Downs – and even further from the Fairport-inspired template of their first three albums (Carbeth, Abandoned Love and The Constant Pageant).

Trembling Bells' lyrics mirror the diversity of the music, mashing together psychic and mythic landscapes, Greek tragedy, obscure religion, Hollywood stars and the dark genius of much-missed writer Dennis Potter (who provided the album's title reference) – all with a playful British anarchy that happily crams “Lou Reed, Lauren Bacall and Asterix the Gaul” into one line, or rhymes 'Zoroaster' with 'ever after'.

Getting all this stuff in demands space, and all but one of the eight tracks weigh in between 5-8 minute mark, full of musical (high) jinks and flamboyant showmanship blending acid folk, Americana, psych-rock and prog – plus an openly-expressed love for the Incredible String Band (they've toured with ISB main man Mike Heron).

Switches in tempo and style abound, most outstandingly in the halting and swooping O, Where Is Saint George?, which begins like a slow shanty before slipping into a borderline mad delivery, while Between The Womb And The Tomb switches between slower sections and high-pitched skittering guitar in a folky pavane. Sweet Death Polka shows a welcome slower side, its seemingly simple country folk growing into something of greater stature, like a British version of Dylan circa John Wesley Harding.

Killing Time In London Fields offers great walls of keyboard and jagged guitar somewhere between Krautrock and Stereolab in their Mars Audiac Quintet-pomp, with the extra guitar firepower adding a garage edge. Bells Of Burford nods to early Doors with a bit of prog chucked in beneath Blackwell's soaring vocal - though it also illustrates one of the album's negative aspects as it wanders into a over-hectic wig-out of tempo shifts and chaotic organ.

While their dramatic ambition and emotional intensity has to be applauded, not everything works. The Singing Blood and I Is Someone Else never get out of first gear in the interest stakes, while the prog-meets-rambling folk (Perched Like A Drunk On A) Miserichord was doubtless great fun to play but not so good to listen to.

But even when things don't work, Trembling Bells stand out as shining beacons of inventiveness. Catch them on their current UK tour.