I can remember exactly where I was the first time I heard the voice of Tom Waits. It was after a sleepless night, finishing second-rate essays for some first-year course of university study. I remember the rush to the head it gave me. It was a very physical sensation, close to ecstasy, no matter how sad the songs – and some of these weren’t cheerful by any standards.

I have similar memories of introductions to other singers I love. And so I will always have a soft spot for Richard Thompson’s Rumour and Sigh, Nick Drake’s Bryter Layter, Tom Waits’ Small Change, Joni Mitchell’s Ladies of the Canyon, John Cale’s Fragments of a Rainy Season.

Ask the critics, and they will probably tell you that these aren’t the best albums by those artists. Maybe they’d be right, but that was where the story started for me, and I’m sure you have similar stories – if you’re young enough to still be buying your music, that is.

Now don’t get me wrong – this is not a rant against iPods or paying for music one track at a time rather than buying entire albums. To tell the truth, any one particular song from those albums I mentioned would have swayed me, but I will say this much: hearing a well-crafted, inspired performance followed by another, and then another, is like a seduction: you can’t believe that there are more surprises up this thing’s sleeve, and there always are more. Songs on an album have a way of standing (or, much too often, alas, falling) together. Sometimes they stand together uneasily, and sometimes the finished product is all the stronger for that uneasiness.

And so, when the rush to the head is over, you’re left with something coherent – and we all need a bit of coherence in the morning.

Why the rush? Well, it’s as if someone has stepped into a kind of no-man’s land, a very intimate place that isn’t on any map they showed you at school. For me it often comes with the quality of a singer’s voice or a well-turned lyric, but then I’m a singer - maybe it’s different with you. The important thing is that you are called into that place, to discover it for yourself.

At some point, while we were rehearsing the songs for our new album, we started playing a song called Tattoo Jesus, about a desperate man who wanders into the Four Star Tattoo Parlour in Santa Fe, New Mexico with a picture of Jesus in the arms of Mary Magdalene. He wants this picture tattooed on his smooth chest. When the work is finished, the tattoo artist’s daughter, who has never spoken, bends down and says one word to him. It is the turning-point of the song – everything hinges on that word, but we never learn what it is.

When we finished playing it the first time, Dave, our irreverent mouth harp player, called out to Barbara, our lyricist, “I love that … But what was the word? You have to tell us what the word was!” He, and all of us, had been seduced by the song, feeling that old rush to the head that happens when worlds meet for a second. Only this time it was one of our own.

That’s why we keep doing this.