Mercury Rev, Islington Assembly Hall review - the august US psychedelic explorers cover all bases

The body language fascinates. Mercury Rev’s frontman Jonathan Donahue could be playing a theramin. The arm movements fit the bill, yet the putative instrument is absent. At other points, his arms are outstretched, palms down. He might be projecting invisible rays in the manner of a silent-screen magician or, when he's in front of the band’s guitarist Grasshopper, absorbing invisible energies.

During “Dream of a Young Girl as a Flower,” his arms – seemingly of their own volition – jolt up and down, tight to his body, a constricted analogue to the movements of Joy Division’s Ian Curtis. Judging by the reactions to some of the ensuing songs, it seems he is mirroring Joe Magistro’s drum patterns. Getting further into the drumming, the singer places his foot on the bass drum, making summoning gestures at Magistro. A whole-body freeze-frame brings to mind the sinuous shapes formed by Nijinsky. Overall, Donahue’s presence suggests the wide-eyed guilessness of a character played by Gene Wilder – an individual caught-up in, and enchanted by, the flow into which they have stepped.

This show’s configuration of Mercury Rev feels optimal

While Donahue is magnetic, he could not be who he is without the music. Or, for that matter, without the other four people on stage. Mercury Rev is a band, one in which each member is integral to the whole. There have been changes over the years, but this show’s configuration feels optimal – even though there’s no bass player. As well as Donahue and co-founder member Grasshopper, there are Jesse Chandler (flute, keyboards, sax), Marion Genser (harmonium, keyboards) and Joe Magistro (drums). This date is amongst a string following last summer’s release of the Born Horses album, Mercury Rev’s first set of all-original material since 2015’s The Light In You.

The shimmering Born Horses is jazzy, akin to cosmic song-poetry with a beatnik edge. Imagining how it could be re-rendered in a live setting was a head scratch. Perhaps it would become of form of spoken-word performance with the enigmatic lyrics enveloped in a free-flowing musical setting? Two-thirds of the way through the set, the album’s “Ancient Love” is performed and, to a degree, the question is answered. After a few minutes, the song breaks down into a lengthy free-jazz freak out intertwining Chandler’s sax and Magistro’s roiling drums. Stunning. This, however, is it for Born Horses. The album’s next track, "Your Hammer, My Heart," is in the set list but not played. Drawing any conclusion about Mercury Rev’s attitude towards their most-recent album from this is probably unjustified as their catalogue is so substantial. There are songs which have to be played.

Of all their albums, the archetypal Deserter’s Songs unsurprisingly gets the biggest nod. The set begins with the album’s “Funny Bird,” and goes on to include its companion cuts “Tonite it Shows,” “Goddess on a Hiway,” “Holes” and “Opus 40.” The set closes with the almost-as totemic All Is Dream’s “The Dark is Rising” (the album’s “Tides of the Moon” is also played). There are a couple of tracks from 2008’s Snowflake Midnight (“Dream of a Young Girl” and “Runaway Raindrop”), as well as the (relatively) early album The Secret Migration’s “Vermillion.” An overview with nothing to leave long-term fans unhappy, as evidenced by the scurrying to the front when “Goddess on a Hiway” kicks off.

'Runaway Raindrop' is the set’s most epic, most mind-expanded excursion

Donahue and Grasshopper are the band stalwarts, and are on the recorded versions of all of these songs. On stage, the latter is a measured, clipped counterpoint to Donahue. Even so, he makes some noise. Magistro is clearly rooted in jazz, but hits and rocks very hard: especially during “Goddess on a Hiway.” When not wailing on his sax Chandler is measured too, with some of his piano cadences nodding to The Doors' “Riders on the Storm.” Genser appears to be about filling in the aural gaps – including the absent bass guitar – while playing lines which float over everything else: the same applies when Donahue picks up his guitar.

It isn’t the most well-loved or best-known songs which fully define the evening though. The closing trio of “Holes,” “Opus 40” and “The Dark is Rising” unite as a climax, albeit one which is foreseeable. Further pinnacles arrive when the band let go. Earlier, the verging-on free-form “Ancient Love, ” is a less-expected highlight. It follows “Goddess on a Hiway.” Before this, “Runaway Raindrop” is the initial signifier of an unalloyed embrace of the way-out, the first journey into inner space. Born Horses hasn’t been side-lined. Instead, its spirit is summoned to reinvigorate Mercury Rev’s past. “Runaway Raindrop” is the set’s most epic, most mind-expanded excursion.

Understandably, then, during “Runaway Raindrop” Jonathan Donahue is at his most animatedly rococo. Fusing Jesse Chandler’s sax with his Yamaha MIDI trumpet, he surrenders to the psychedelic storm. He’s having fun. As, indeed, is everyone else at this wonderful show.

• More New Music reviews on theartsdesk
• Kieron Tyler’s website

@kierontyler.bsky.social