Younger readers might not believe this, but there were a few months back in 1995 when it was impossible to enter a room full of twenty-somethings without hearing Portishead's ‘Dummy' CD playing in the background.

The band's mix of post-rave chill out music, hip hop and torch song gloom was mysteriously titled ‘trip-hop' by the press at the time. Which was odd, as there was nothing remotely psychedelic about their music. Rather, the band delivered a crushing dose of reality, repeatedly reinforcing the bad news that all love is doomed and there's absolutely nothing we can do about it.

1995 was not a good year for parties.

Hardly the most prolific of creative forces, Portishead have managed to produce only two more studio albums since then. But if last night's show at the cavernous PNE Forum proved anything, it's that productivity is irrelevant in the mind of fans, most of who viewed the entire occasion as a near religious experience.

"Well, good evening," mumbled singer Beth Gibbons after the first two songs.

Those would be the only unsung words she uttered until giving thanks to the crowd at the show's end. Hunched over and clamped onto the mic stand, Gibbons' performance was a virtual "what not to do" demonstration of how to work a crowd. Minimal movement. Eyes closed. Zero communication. And yet, it was her bizarre intensity and connection to the music that made this show work and kept her audience silently worshipping in reverence. Although she is technically one-third of Portishead, her uniquely mournful voice was the undisputed star of the show. Without her, it's just a bunch of dudes playing music painfully slowly.

In theory, it was all dance music. In actuality, the pace of most of Portishead's set was far too lethargic to genuinely boogie along to. A few brave souls tried, but couldn't quite manage to make it look convincing. Anyone old enough to have been there when Portishead first emerged understood that this wasn't music to dance to anyway.

Which suited the majority of concert-goers just fine. The theme of the night was always going to be mid-90s nostalgia and the biggest cheers were reserved for the tracks from ‘Dummy' – ‘Mysterons', ‘Sour Times,' ‘Glory Box' and ‘Roads'.

Although Portishead did a fine job of recreating the eclectic electric sounds, snail-paced beats and maudlin atmosphere of their debut masterpiece, the evening's highlight came when the band chose to deconstruct one of that album's best tracks. Dismissing all but the core members of the band – Gibbons, Geoff Barrow and Adrian Utley – the three played a haunting reinterpretation of ‘Wandering Star' with just guitar and bass. None of them so much as glanced at the crowd for the entire duration of the song, Gibbons' stark deliverance of the none-more-bleak lyrics, "Please could you stay a while to share my grief," culminating in an astounding but harrowing blast of vocal virtuosity.

For all their critical plaudits, Portishead have always been a one-trick pony; that pony going through a really messy break-up and addicted to crystal meth. But this is music that refuses to apologise for its own misery. Last night's show was neither a party nor a chill out session. It was something far more intense and far darker.

Midway during the finale of ‘We Carry On' Gibbons climbed off the stage and walked along the front row of the crowd, shaking hands and exchanging hugs. She returned to the stage to wave goodbye with a beaming smile. The huge crowd, fed on unrelenting bleakness for the previous hour and a half, were doing the same.