POLLY HARVEY was on home turf for her comeback show on Friday night. Making her first UK appearance in two years, the internationally acclaimed blues-rock siren launched her latest European mini-tour at Cornwall’s spectacular Eden Project, not far from her Devon home.

Harvey’s stripped-down backing band numbered just two: John Parish on drums, and the multi-instrumentalist Mick Harvey — no relation — on loan from her former lover, Nick Cave. From the low, masculine moan of To Bring You My Love onwards, she was electrifying. Prowling the open-air stage in white tunic, bare legs and black boots, the diminutive, unassuming singer seemed transformed into some kind of towering she-devil.

Good Fortune sounded gutsy and booming, its rolling yodel chorus rebounding heartily around Eden’s natural amphitheatre. The howling mania of 50 Foot Queenie provided another early highlight, and Snake was splendidly splenetic, a staccato barrage of insults hurled like poison darts.

Visceral physicality is one advantage that Harvey’s live shows have over her records. Attacking her songs with piercing howls and discordant crackles, the effect on anyone within 50 metres is rather like being whacked over the head with a vintage 12-string guitar.

And while her sound may be grounded in a bone-shaking blues primitivism, what distinguishes her from retro-fetishist minnows like the White Stripes is the rich emotional landscape she seems to inhabit, a primal swamp of bare-fanged lust and gender-twisting mania. It’s all artifice, no doubt, but it’s riveting music.

Two new songs were aired midway through. Who the Fk? proved as uncompromising as its title, with a hammering, percussive structure that suggests Harvey’s bluesy muse is embracing a funkier side. The confrontational lyric was equally strident, a tirade against the unwanted advances of some creepy stranger or ex-lover. Next came a mellifluous lament, apparently titled Sweeter Than Anything, which shifted down a gear into desolation and regret. Both bode well for Harvey’s next album.

Alas, during its final third, the show began to drag. Maybe it was the magical setting, but Man-size lacked its usual malevolent bite and Rid of Me felt more like a cosy crowd-pleaser than a queasy fem-punk bruiser. During her mammoth seven-song encore, Harvey seemed a little too comfortable playing fairly orthodox blues-rock. In fairness, this is her turf. But she’s more thrilling when she leaves us unsettled, not simply entertained.