"Thank you for joining us on this fucked-up journey." Juliana Hatfield is talking about this gig, a stripped-down, two-person show banjaxed by technical problems. Her co-headliner plays a guitar borrowed from the support band and, periodically, all the power goes out.

But she may as well be referring to the 25 years that she and Evan Dando have been making music; sometimes together, mostly apart. In the 90s, they were Boston's platonic, power-pop couple, leading the Lemonheads and the Juliana Hatfield Three respectively. They traced more erratic arcs in the 2000s, but remained close; and despite somewhat asymmetrical fame in the UK, this tour is pitched as a double header.

The vibe is offhand, and they bat songs between each other with lived-in ease. "You do one, I'll do one," says Dando. Both are gifted songwriters: Hatfield's Somebody Is Waiting for Me recalls the Pixies in their pomp, and Dando's Confetti is an effortless, easygoing round. There's no room for Mrs Robinson, the cover that gave the Lemonheads zest, but there are impassioned readings of Streets of Baltimore, made famous by Gram Parsons, and Pale Blue Eyes, made memorable by Dando's iffy guitar solo.

The moments that truly snap into focus are, for the most part, songs for which Hatfield has originally recorded backing vocals, her breathy contributions adding Proustian flashes to My Drug Buddy and It's About Time. Dando's best work arguably remains fresh by sounding slightly dashed off – even after 20 years, he has resisted coming up with an actual ending for goofy love song Bit Part. The apex of the technical meltdown finds Dando playing Tenderfoot, alone and without amplification. The crowd sing along in a hushed murmur, and amid this chaotic hangout, it's a moment to treasure.

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