In a less-than-glowing assessment of Schubert's music, Mahler stated that "each repetition is already a lie," referring to the earlier composer's forms and structures. The statement seems confusing coming from Mahler, whose rotational forms and variant techniques involve frequent quotation, not only of folk songs and march tunes, but of himself – his own songs and symphonies. Michael Tilson Thomas, leading the San Francisco Symphony in an invigorating performance of works by both Schubert and Mahler, emphasized the idea of repetition as an evolution rather than a lie. Their performance of Schubert's "Unfinished" Symphony, lukewarm yet ultimately gratifying, was followed by a riveting performance of Mahler's Das Lied von der Erde.

The "Unfinished" Symphony, set aside in 1822 and left uncompleted at the time of Schubert's death in 1828, consists of an Allegro and a slow movement. Although various additions have been composed over the years, the symphony is typically heard in this two-movement form. The San Francisco Symphony brought a crisp sound to the first movement, though occasionally it became muddled as sections of the orchestra fell out of sync with each other. Mr Tilson Thomas pulled them into smoother, much more delicate playing upon the repeat of the exposition, as if telling the audience, "Okay, now that you've heard this melody once, you can take the time to enjoy it." During the development section, the sound deepened and intensified, only for Mr Tilson Thomas to pull back again, leaving the thicker sounds hanging in the air. The second movement was less energetic, with conductor and musicians again not quite together. However, the serene (if premature) ending of the symphony nonetheless brought a sense of closure.

Mahler's own unfinished symphony, his tenth, was left incomplete at the time of his death in 1911; Das Lied von der Erde was composed in 1907 and 1908, predating his Ninth Symphony and superstitiously avoiding that title. The Austrian composer and opera conductor desperately yearned to avoid the trap that had snared both Beethoven and Bruckner, neither of whom had lived beyond their ninth symphonies. Instead, Mahler called his composition Das Lied von der Erde, with the subtitle "Symphony for Alto and Tenor Voice and Orchestra." Mahler's fears were not only grounded in superstition; he had become increasingly aware of his mortality after the death of his four-year-old daughter, and his own diagnosis with a serious heart condition, both in 1907. The 60-minute Das Lied consists of music set to six poems from Hans Bethge's German translations of Die chinesische Flöte (The Chinese Flute). The final song, "Der Abschied" (The Farewell) was Mahler's fraught acknowledgement of the closeness of death.

The orchestra, now twice as full in sound and presence, was joined by tenor Simon O'Neill and mezzo-soprano Sasha Cooke, both of whom brought fullness yet clarity to the vocal roles. The orchestra, stretched to Mahlerian extremes, was here taut and balanced, shrill when necessary, loud to the point almost of painfulness when pushed there by Mahler's indications and Mr Tilson Thomas's rigorous conducting. Das Lied possesses its own sense of repetition, with Mahlerian quotation and paraphrase running in undercurrents through the work. The sounds of the third song, "Von der Jugend" (Of Youth) – imitations of birdsong in the woodwinds, jaunty overlapping rhythms seeming to indicate a spring in the step of the narrator – embodied a utopian innocence. These contrasted strongly with the many rhythms and timbres of the next song, "Von der Schönheit" (Of Beauty). These rhythms and timbres, spliced together and culminating in a whiplash-inducing polyphony, seemed to convey the entire course of the world – beauty and ugliness combined. Mr O'Neill brought not only beautiful singing, but the self-consciousness of false triumph, to "Der Trunkene im Frühling" (The Drunkard in Spring), while the darkened human tones of Ms Cooke's solemn vocalization of "Der Abschied" contrasted with optimistic flute and bassoon lines. Mahler's final song reveals the distance from the youth and innocence heard earlier. Mr Tilson Thomas steered the orchestra to the brink of collapse before pulling them back towards their quiet resolution, a flawless embodiment of calm resignation in the face of mortality.