With Twin Peaks, it was like falling in love. I was too busy being a self-absorbed student of literature to watch David Lynch and Mark Frost's TV serial, and deeply strange work of art, when it started to be shown in different versions in the late Eighties and early Nineties. But, by the time I had finished watching its pilot episode for the first time, last year, I knew I was hooked for life. All the symptoms of middle-aged dotage followed (think Death in Venice): sleepless nights, drowsiness at work, lying one's way out of dinner plans with friends, and a churning in the guts all day in anticipation of the night's pleasures - that mix of terror and thrill, so beautifully captured by Visconti and Bogarde, with lots of help from Mahler and Venice.

Like love, Twin Peaks meant total immersion in the mysteriousness, and truth, of another person's imaginary universe, without any irritable reaching after fact and reason. It was immersion, also, in a vision of evil and, inseparably, of good. I remember, as a student, how difficult, even absurd, it was to write academic essays on poems like the "Ancient Mariner", "Christabel" and "La Belle", or stories like "The Turn of the Screw". Yet, when we read them out to one another, or later when I read them out to my students - that is, when we allowed ourselves to experience them musically, sensually or cinematically - it would all make sense, somehow: the darkness, the confusion and the beauty, the confounding of evil and good, of what lay 'out there' in the night or at sea but also held us close in our sleep and got into our heads.

Twin Peaks revived those youthful memories in my body as I devoured both seasons in a week. As I watched the episodes late into the night, I would look up, from time to time, from my laptop screen at the curtained door that faced me. The curtain hid the veranda and the garden beyond. It trembled in the breeze of the fan without being lifted enough to let me look outside, and suddenly my study with its stone-cold red-oxide floor would become the Red Room (wasn't Jane Eyre also locked up in a red room as a child?), and the garden - which I couldn't see but knew had been turned by darkness and moonlight into the negative of a garden - was where the Black Lodge and the White Lodge would begin to glimmer and merge. A couple of months ago, Lynch was asked in a public conversation about his journey from being a painter to making his first full-length film, Eraserhead, in 1976. He thought for a moment and began describing his student cubicle at the Pennsylvania Academy of Fine Art: "I was in the cubicle, one night, painting a garden at night, mostly black with some leaves, green, coming out, and I was sitting looking at this painting, and from the painting I heard a wind, and then I saw the green start to move, and I said, ' Oh, a moving painting!'" But the interviewer failed to get anything more than a stubborn smile on pursuing this further.

That wind, I realize, had reached me not only through the painting that had been made to move on my screen, but also through the acoustical space created inside my head by my headphones. During the day, as I did my chores with Angelo Badalamenti's music for Blue Velvet and Twin Peaks playing on a loop, I felt the extent to which this serial thriller and Lynch's best films rose out of the sea of this music, like the sound of the foghorn that haunts the film, or Laura Palmer's pearl-grey corpse wrapped in cellophane.

With the films in which they collaborate, Lynch and Badalamenti talk passionately together as the latter improvises and composes on the keyboard. So, the stories, characters and atmosphere in each film or episode are brought into being through the making of this music and conversation, rather than the other way round. Sometimes, the musical origin of a film is in a popular song - like Roy Orbison's "In Dreams" for Blue Velvet (1986) - recalled by the filmmaker and revived by the composer. This mingling of the filmmaker's soul with that of the composer - a process involving the sharing of the conscious as well as the subconscious between them, and driven as much by intuition as by craft, by an openness to the other's inner life as by being in touch with one's own - is also what these films are, so to speak, 'about': the synchronous and symphonic nature of experience, or Life, itself, and of the stories, both singular and unfathomably interconnected, through which lives are lived, and Life unfolds.

It was through such traffic between filmmaker and composer that the musical motif linked with the mystery of Laura Palmer's death came about in Twin Peaks - a process vividly described by both in separate interviews. And every time I heard that ominous, dream-like music, it took me to the brink of a highly specific musical memory, which kept eluding me. I was sure that I had heard those intervals and, more important, felt those emotions before - purely musical emotions impossible to put in words. Then, one night, lost in a labyrinth of YouTube links, I began listening to Benjamin Britten's Serenade for Tenor, Horn and Strings - a song cycle composed in the early Forties, when Britten was in hospital with measles. When I came to the fourth song, a setting of William Blake's "The Sick Rose" from Songs of Innocence and of Experience, and heard the throbbing plaintiveness of its musical prelude and the shamelessly putrid horniness of the solo horn's closing wails, pushing far beyond the human voice of the tenor, I realized, with a quickening of the pulse that accompanies such moments of sudden fathoming, what the Laura Palmer music had been reminding me of. As a student of the classical horn in his youth, Badalamenti must have known, possibly even played, this music, and it had seeped into his musical realization of Laura Palmer's story.

As a teacher, I often use Blake's dense little poem, together with his hand-coloured etching of it, to introduce my students to the rich-and-strange of poetry. An entire novel at once Gothic and modern, a whole universe of characters, setting, action and atmosphere, yet forever eluding a definitive interpretation, remain condensed in the two short stanzas of the poem, across which its two sentences are syncopated. The first sentence is a terse address: " O Rose thou art sick." No exclamation mark. This diagnosis is then spelt out in an inexorable sentence, cut in the middle by the stanza-break: "The invisible worm,/ That flies in the night/ In the howling storm:// Has found out thy bed/ Of crimson joy:/ And his dark secret love/ Does thy life destroy." Suddenly, read and heard alongside Lynch and Badalamenti, I began to see how Blake's dark matter could be illuminated by - and, in turn, illuminate - not only the sickness at the heart of the coffee-and-cherrypie world of Twin Peaks, but also the deep, deep kink of Blue Velvet, which is, for Lynch, "a dream of strange desires wrapped inside a mystery story".

"I have your disease in me now," Isabella Rossellini says, more than once in Blue Velvet, to Kyle MacLachlan as they make what some would hesitate to call love. (Her exact words are echoed in French during a similar, but more extreme, scene of inscrutably induced violence in Michael Haneke's The Piano Teacher of 2001.) It is the same boy actor, MacLachlan, who grows up in Twin Peaks to come face to face, once again, with the same sort of secret contamination. In Lynch, as in Blake, it is a sickness that resists both psychic eradication and moral judgment. For both artists, it connects, not just symbolically but in a more organic way, human sexuality with the natural world of real worms that devour and are devoured, and of real roses that bloom, sicken, die and rot. (Incidentally, this makes me wonder, in a human context, about the difference between You are sick and You make me sick. Aren't they two distinct, but equally insidious, speech-acts of intimate violence?)

While talking about the world in which Blue Velvet happens, Lynch moves seamlessly from a vision of America to a vision of life: "There is a very innocent, naive quality to life, and there's a horror and a sickness as well." Apparently, the only book that an interviewer once found in Lynch's office was Blake's poems. Going back again to the Songs, with a naked man and woman crushed by giant tongues of flame on its cover, I found on the title-page Blake's description of the book as "Shewing the Two Contrary States of the Human Soul". In the courtrooms of academic learning, would this count as evidence of a profound connection between the two artists? It was not scholarship, but music and memory - a kind of associative and intuitive listening - that had led me to the spectre of Blake's rose at the heart of Lynch's America. As in the sublimely dubious investigative methods of Agent Cooper in Twin Peaks, it was intuition that had turned out to be my inner detective. "I think that intuition, the detective in us," says Lynch, "puts things together in a way that makes sense for us." But this "inner knowing", he adds, is hard to communicate to someone else.

But not always so. The last time I was in Venice, I took along to a dinner hand-outs of Blake's "Sick Rose" instead of wine, and we sat around the table and read the poem together between main course and dessert. I didn't know this when I chose the poem, but our host had just finished a book on the history of a rose that the Chinese had brought to Venice via Calcutta. It was in bloom in the garden by which we sat, and made bold by these coincidences, and by the shedding of inhibitions thanks to the poem, I shared my Lynch-knows-Blake theory with my friends. I was thrilled when everybody got it straight away. The talk drifted randomly from Blake's rose to Citizen Kane's terminal "rosebud" to Mahler's Röschen rot to Rilke's French roses. Someone remembered that Cy Twombly's late rose paintings were on show at Ca' Pesaro, and the next day I found myself standing in front of those great, sullied monsters of mystical beauty with a friend - another coincidence - who keeps capturing the souls of real flowers, especially roses, with her phone camera. High above the drips and smears in one of his panels, Twombly had copied Rilke's lines about the rose as "sheer contradiction" - "no one's sleep under so many lids". These words are also carved on Rilke's gravestone, as he had wanted. But that is another story - or is it?