Last things in art are something I've been thinking about more than usual over the past few months, performing in recital and recording in the studio Schubert's last song-cycle, Schwanengesang (Swansong) - his publisher's posthumous title. It's rather a mystery piece, with two groups of songs: seven settings of Ludwig Rellstab and six of Heinrich Heine, apparently disconnected but which the composer chose to write out as a single sequence in manuscript. In performance, despite all the theories of musicologists over the years, the manuscript order and single span of 13 songs seem to make a sublime (if difficult to pin down) aesthetic unit.

But Schwanengesang as printed in 1828 consists of 14, rather than 13, songs, and not just because the publisher Tobias Haslinger was superstitious. He added, as a postscript or envoi, Schubert's very last song: the charming, lilting "Die Taubenpost" (The Pigeon-Post), a poem by Johann Gabriel Seidl. In doing so, he offered us a vision of two sorts of sublimity. Late works, as John Updike has put it, "exist, as do last words, where life edges into death, and perhaps have something uncanny to tell us". Just as children offer a prospect of authenticity, so too do those at the end of life. Everything Schubert wrote after 1823, when he was diagnosed with syphilis and faced the prospect of insanity and death, constitutes late work.

The Heine settings of Schwanengesang, in their awful simplicity and starkness, in their radical abandonment, for the most part, of the melodic impulse, offer one approach to encroaching finality. They still shock and they seem to reach far beyond the poems of lost love upon which they hang.

Yet Schubert's hauntingly melodic and wistful "Taubenpost" seems to encompass a pulling-back from pessimism, cosmic or otherwise, and an embrace of life's rich if melancholy dance.