A small bit of history, last night, that I was honoured to witness. Wilco played at the Shepherd’s Bush Empire in West London, the scene of some pretty fractious shows by Jeff Tweedy – a fact which made him both self-conscious and extremely funny when he found the courage to open his mouth.

Wilco were great, of course. I’m currently going through an intense Grateful Dead phase, and so consequently a lot of music reminds me of them. But when Wilco started with “Side With The Seeds”, I’m fairly sure the comparison is valid here. It’s a kinship with early ’70s Dead, I think: that rootsy, soulful feel; the way the band play with such a relaxed and intricate swagger; the easygoing virtuosity, focused on the astonishing lead guitarist, Nels Cline.

The new Wilco album, “Sky Blue Sky”, has been accorded some rather middling reviews over here, with a bunch of critics bemoaning that Tweedy has abandoned the experimental imperative (wrongly, I’d argue, and did here). But the new songs fit in just fine alongside great workouts like “Handshake Drugs” and “Via Chicago”. Pat Sansone now seems to be playing more guitar than keyboards, and there’s a fantastic passage towards the end of “Impossible Germany” when he and Tweedy play twin lead while Cline, a lanky and juddering eccentric in waistcoat and half-mast trousers, steps up for a scrabbling, high-frequency solo.

If I have a criticism, though (and it seems churlish, given the general excellence of the gig), it’s that Wilco are a little bit too tight and economical. They might have the feel of the Dead, but they rarely really let themselves go. Occasionally, I want these songs to loosen up and stretch out, to move in ways unpredictable even to the band. “Spiders (Kidsmoke)” remains the highlight, because it shows how this superlative band can combine great, tight songwriting with a little more improvisational risk.

Petty gripes aside, I should get to the most important thing. After nearly two hours, Tweedy called on a special guest, and a slightly sheepish looking greybeard came on. This, amazingly, was Bill Fay – a big hero of mine, as regular readers of Wild Mercury Sound will know. Fay’s three albums are incredible treasures of British music, which I could vaguely describe as a cross between Syd Barrett and Scott Walker, though such simplification does them a gross disservice. I think we have a track from his first album on the next free Uncut CD.

Anyway, Fay hasn’t been on a stage for over 30 years, though an ongoing mutual appreciation between him and Wilco meant they almost talked him into a duet at Hammersmith Apollo on the “Ghost Is Born” tour. Both Tweedy and Fay have talked to me about all this, and I feared that their anxious desire not to disturb each other might mean they would never get it together.

But they do. Fay duets on a version of his own, gorgeous “Be Not So Fearful”, his warm and quavering vocals buried a little behind those of Tweedy – I suspect because Fay was too nervous to sing on his own. It’s a wonderful moment, though. Let’s hope that one of our greatest and most neglected singer-songwriters can be gently eased back into the spotlight now – like another auspicious recluse, Vashti Bunyan, was a couple of years ago.

I wonder if Fay will turn up again tonight? Allan is going along, so I’m sure he’ll file something if he does. I’ll be elsewhere, watching the mighty Ghost. See you tomorrow.