Fifteen years in the making, Bjørkø – the solo project alias of Amorphis guitarist Tomi Koivusaari – is a triumphant journey across the progressive metal landscape, harnessing the artist’s clearly massive talent; Koivusaari has used his time in the mothership wisely, building a big contact book into which he’s dived time and again here, giving not only an all-star feel to the project but also a diversity of thought and approach from the guests which not only keeps things fresh but, with judicious placement, also hits the bullseye times again in terms of song placement.

I’m not actually a big fan of using a different vocalist on every song, but my this approach works in spades here; Heaviest track, opener Heartrot, is perfectly suited to the vocal talents of Carcass frontman Jeff Walker, and he brings the song home with a bravado delivery that few could touch.

It’s a great start, but the fun doesn’t stop there; Sólstafir throat Addi Tryggvason adds real presence to the lurching stadium metal of Vaka Loka, whilst Marko Hietala and Paatos‘s Petronella Nettermalm add a certain Beauty and the Beast dynamic to the classy Whitebone Wind.

Clearly your own preference is singing style is going to have some bearing on the tracks that stick out for you personally, but for this writer the big plaudits must go to Ismo Alanko, whom I’d never come across before apart from an appearance many moons ago as a guest of Finnish quirkmeisters Waltari. His Saturnine presence on the superb Värinvaihtaja adds real substance to the track, rewarding Koivusaari with one of the best performances on the album.

The inimitable Shagrath adds suitably massive amounts of mayhem to World as Fire and Hallucination, whilst Jessi Frey’s schizophrenic performance on The Trickster underlines the themes of the song perfectly.

Inevitably, the most ‘Amorphis’ track here, Hooks In The Sky, features a vocal from that band’s vocalist Tomi Joutsen, but the tribute to the day job slots in perfectly with everything else here, underlining the supreme job Koivusaari has done in giving Heartrot the cohesive feel it has despite revolving door of vocalist. Props are also due to the ‘backing band’ of Opeth‘s Waltteri Väyrynen (drums), Lauri Porra (Stratovarius, bass) and Janne Lounatvuori (Hidria Spacefolk) on keyboards, all of whom work tirelessly to build the band feel of the album.

Closing track Magenta, featuring vocals from another singer I’m not overly familiar with, Mariska, closes proceedings in woozy, alt.proggish fashion, and you’d have to note in summary that the mashup of styles here works supremely well. Fifteen years is a massive gestation period, but Heartrot was definitely worth the wait…

Heartrot releases on December 1st.