I found myself in the Anchor bar last Sunday afternoon. The Anchor is famous for its juke box, which annually wins the poll for ‘best juke box in New Haven.’ But the juke box was not playing, though its yellow lights flashed. Instead, someone behind the bar had put on the CD which contains ‘Ella and Louis’ and its follow-up ‘Ella and Louis Again’. I’d meant to stay for just one drink but I love that record so I sat in a booth and listened to the whole CD. I’ve known ‘Ella and Louis’ for decades, but I have never heard it played in its entirety in a fairly large, public space before. It would be wrong to imply it was like hearing it for the first time, but I was certainly hearing it differently. It was like hearing a remastering which brings new details forward, the vaudevillian absurdity of ‘Let’s do it’, the deep melancholy of ‘Willow weep for me’, the wistful yearning of ‘Autumn in New York’.

The Anchor is a dive bar from the old, weird America which exists now only in traces. You will not find ‘craft beer’ here, or a wine list. The walls are a very deep red. The seats in the semi-circular booths are brown plastic and not awfully comfortable. Mirrors above the booths reflect the darkness. It is always dark here. It smells of cigars, because it is right next to a cigar bar, the only bar in the city where it is legal to smoke, and the smoke curls pleasingly round to the Anchor. On cold days an old space heater is placed in the middle of the room, which emits a worrying smell. On a Friday night The Anchor is packed, with older couples out for a bite of diner-type grub, and office people relieved at the coming of the weekend and students who enjoy its retro-non-hipness which is a kind of hip. Also, working class men alone, sitting on stools at the bar, reading the New York Post. The tiny bar is in the far corner: three people and it’s taken up. This Sunday afternoon there are five people in the Anchor plus me. Two of the five are staff. They have all fallen silent: they are listening to the music. It is music that makes you listen. Louis Armstrong always has that effect.

Ella and Louis’ is a series of duets between Louis Armstrong and Ella Fitzgerald. It removes Armstrong from the context of his band. The accompaniment is instead by the pianist Oscar Peterson, the drummer Louis Bellson and the bassist Ray Brown, a classic mid-fifties mainstream jazz line-up. The cushion of Oscar’s piano is not a sound I associate with the Anchor, where normally seventies pop is playing on the jukebox and a smattering of early rock ‘n’ roll, but it lights up the room. Ella sings with sublime creaminess.

But Armstrong is something else entirely.

It must have been astonishing to hear these recordings the day they came out. The song choice is high end pop songs of the day, Cole Porter, Irving Berlin, the Gershwins, the kind of ‘sophisticated’ lyrics Armstrong had rarely recorded before. Lyrically and emotionally very different from ‘Tight like that’ and ‘Big fat ma and skinny pa’, two of his twenties masterpieces.

As a rule of thumb, it’s ‘the voice as an instrument’ (to use a cliché) that distinguishes great jazz singers from commercial vocalists, Billie’s voice or Betty Carter’s or Anita O’Day’s working like saxophones, the singers thinking like players. (Anita O’Day dressed like the musicians in the band, to say, hey, I’m a musician.) Everybody knows about the sublime musical love affair between Billie and Lester Young: Lester’s sax his voice, Billie using her voice as an instrument. This doesn’t explain Armstrong, whose voice is an extension of his instrument. There’s a beautiful fifties blues where he plays a trumpet obbligato to accompany his own vocal, the horn and the voice speaking to each other, responding to each other. He claimed to have invented scat singing – the wordless vocal – and he is certainly the first person to scat on a record. And yet he gets to the depths of words. The poet Philip Larkin put it well: Armstrong “tears lyrics up by the roots.” He was as deeply musical as it is possible to be, but he was also a profoundly word-driven man. If you’ve seen footage of him talking you’ll know what a wonderful interview subject he was. He was also a writer, though, born into abject poverty in red light New Orleans, he was lucky to escape illiteracy. He travelled with a typewriter, and wrote in the tour bus, in hotel rooms, in his dressing room. Reams of stuff, much of it published a few years ago. Letters, reminiscences, essays. So when he sings, the stretching of a vowel here, the emphasis of a consonant there (‘Louissss…’ ‘The Britishshsh Museum….’ ) may have a musical beauty, but it serves the lyrics too. I noticed listening in the Anchor how absolutely limpid his line readings are, the kind of clarity Gielgud brought to classical texts. Before the ‘Ella and Louis’ sessions it might (I suppose) have been imagined that the frosty, elegant wit of Cole Porter was not in his range, but it has never been done better.

Halfway through ‘Let’s Do it’ a new customer came in and went to the bar and ordered a drink which he took to a booth. He too was listening.

When the album finished I drained my glass and went out into the daylight, which was bright and sunny. I was exhilarated. I reflected on how much I love Armstrong and what a giant artist he is. But as always with great art, there is ambiguity. In the middle of my exhilaration, I remembered what Billie Holiday as a girl had said when she first heard him: “How can a music that is so happy seem so sad?”