Time is the stuff of music: music manipulates our experience of time; it plays with the rhythm of experience; it stretches and complicates our relationship to the passing of time. If the world of physics is a space-time continuum, music is a pitch-time continuum. We use spatial metaphors to express our experience of frequency - notes are higher and lower, something expressed formally in staff notation, and deeply inscribed in our experience of music as performers and listeners. A large interval between two notes is a gulf to be stretched over. The quintessential musical form, melody, as it moves up and down in pitch space, over time, is a sort of quasi-miraculous bridging of the gap between the abandoned past, the ungraspable present and the as-yet-to-be-achieved, utterly unreal future. We grasp it and, as we do so, time is attended to and made palpable and affective.

It's no coincidence that the great age of music as metaphysics - Schopenhauer above all - coincided with the construction of larger and more complex forms in classical music. These brought a specialised form of rationality, musical rationality, to the subjective experience of time, through both the eked out, endless melody of Wagner, and the great symphonic structures of Bruckner and Mahler. Nineteenth-century music's ambitions for itself were in many ways as cosmic as the Pythagorean vision of an art form in tune with the construction of the universe itself, the music of the spheres. It wanted to mirror the ebb and flow of being itself.

While this all seems impossibly grandiose in a postmodern age, classical music still has the capacity to generate visions of the sublime. Here is Daniel Barenboim, recently quoted in the International Herald Tribune: "Since every note produced by a human being has a human quality, there is a feeling of death with the end of each one, and through that experience there is a transcendence of all the emotions that these notes can have in their short lives; in a way, one is in direct contact with timelessness."

There does seem a sort of affinity here between musical ambitions and the kind of metaphysics disdained by Anglo-American analytic philosophers. Karl Jaspers (1883-1969), for example, wrote of the possibility of certain experiences as "instants of eternity in time", of a human capacity to be transported to an eternal present. Surely music is one of these routes to epiphany?