Arbouretum - Song of the Rose (Thrill Jockey)

Described fairly in the past as a 'guitar-fuzzed powerhouse', Baltimore-based quartet Arbouretum - Dave Heumann (guitar/vocals), Corey Allender (bass), Brian Carey (drums) and Matthew Pierce (keyboards) – seem in more contemplative and exploratory mood on this sixth studio album.

After 15 years of working via rough-edged semi-improvised jams, Arbouretum have decided to foreground some new elements. This augmenting of the familiar sound is flagged up on the opening Call Upon The Fire where, after six minutes of typically appealing melodic guitar crunch, there's a coda featuring noodling keyboards and – wait for it – acoustic guitar.

Just to show this isn't a gasp-inducing one-off, Heumann goes acoustic again on a couple of more heavily folk-influenced tracks. The acoustic elements and pensive, fragile vocal on the ballad Comanche Moon suggest an out-take from a Crosby-Stills-Nash session in Laurel Canyon's 1960s heyday, while the closing Woke Up On The Move conjures images of a great session in a Galway bar.

A similar folk thread runs through the jaunty Absolution Song, with its lyrical references to running stags and historic references to further 1960s predecessors like The Incredible String Band.

None of this is to say Arbouretum have turned to fey Americana. Far from it – there's a solid heft to all the tracks with these new elements enlivening the old familiar beloved template. The desire for trying some novel sounds is there too in short-but-intriguing Mind Awake – Body Asleep. Whereas seven of the eight tracks stretch out to the 7 or 8-minute mark, this blend of deep bass rising into a fierce guitar maelstrom has an exhilaration that makes you wish it lasted more than a minute or so.

The title track is a rousing mid-tempo masterpiece stretching towards the 10-minute mark with a mix of declamatory vocals embedded in a wall of hypnotic guitar riffs, while Fall From An Eyrie manages to sound like a crowd-pleasing stadium singalong number with more class than that kind of thing normally has. Only the rather ponderous ballad Dirt Trails disappoints.

With a title song that takes inspiration from a 17th century poet, Song Of The Rose showcases a more rounded side of a band whose often mystical lyrics and well-crafted musicianship make guitar music into a form of aural poetry in itself.