Perhaps I'm prejudiced toward one of my very favorites, but I wish to submit the string quintet D956. I'm thinking in particular of three character traits:
(a) the way Schubert attempts to reconcile his compact melodic genius with his ambition to write something bigger. The piece contains some of his most breathtaking melodies - especially the one in the first movement, which I think the most beautiful melody he wrote though there are so many to choose from, treated like a self-contained miniature lied, almost! - but they are built into an enormous edifice, the kind of grand-scale work he started writing very prolifically as he reached maturation (late sonatas, C major symphony).
(b) the attempt to solve the "finale problem." His "Little" and "Great" symphonies have very eccentric finales, I think, and the two he built for D956 and D960 are very similar in that, from an emotional standpoint, they seem (<-note word choice) circumspect and detached from the emotional core of the piece. But in D956 he solves the problem very neatly, and the final three chords, so weirdly jagging from triumph to terror, summarize in a single second my third point -
(c) the violent juxtaposition of opposite emotions. Also something you see in the song cycles and the last symphony's slow movement, among other places. The thing that fascinates me about Schubert, and about this work especially, is the close quarters sublimity keeps with raw, naked anguish. Besides the final chords, the two inner movements are most important here, especially the scherzo, which brings elation and the deepest, most melancholic sense of loss. It's a paradox, and I think Schubert is full of such paradoxes, such abrupt and confrontational exclamations: "look here: I feel this way, and that way, and perhaps you think no human is capable of feeling both, and yet I feel these things simultaneously."
Brian, thanks for this superb post. You vindicate what was my idea behind this (and the other threads): what is it that
you think makes this composer great/sublime/unique, and can you ascribe these traits or qualities to a single work? By getting such detailed
personal analysis, we can all benefit from each other's unique opinion on a composer that everybody considers great, but who also competes with dozens of other great minds.
I've already mentioned a few times something that I read when I was a teenager and that has stuck with me for almost 40 years: the sculptor/artist/goldsmith Benvenuto Cellini held that a work of art must be viewed from eight different angles, each one offering a perfect perspective. Well, you get the idea: a work of art is more than the sum of its parts, and yet each part must give you a valid POV on the whole.
I emphasize again that I don't intend to find THE greatest work, the most representative, the best entry or best whatever to the composer in question. It is true that a single work cannot encapsulate ALL that makes a composer great (I honestly think that is impossible to define in some cases, like Mozart, Haydn and JS Bach. in the case of Schubert and Beethoven we can always try

.
Back to
Schubert: I hesitated between chamber, vocal, instrumental and orchestral. I quickly decided that orchestral Schubert, however much I like it, is no the best way to get the essence of the composer. Some of these works are uneven, others are like the child who becomes an adolescent in a matter of weeks: no clothes or shoes can contain his suddenly bigger, elongated self. He has outgrown everything he used to wear. For that same reason I also decided against any 'low' Deutsche number - say, under D.800.
Vocal: lieder, masses, operas? The latter are not well known and it's possible they're not really very good. Single lieder? Can a short voice and piano work tell me more than the rest of his huge output? I can say yes in just one instance:
Der Hirt auf dem Felsen (Shepherd on the Rock). It has been and will always be THE Schubert short work I love above any other. I never tire of hearing the introductory 'once upon a time' piano declamation, the 'stretching out of noonday slumber' clarinet succulent, self-satisfactory, Cherubino-like aria, and the radiant, innocently erotic Ode to spring from the soprano. And the joyous, happy homecoming of the trio in the allegro last section. What joy, what innocence and relish of life!
Instrumental: piano of course. In this case there are a few works that singly (sonatas) or as a mini-corpus (the grouped opus something works such as the Impromptus, Moments Musicaux or 'Klavierstücke) could be thought of. As
Caughtinthegaze suggested, D.959 is an obvious choice. Possibly the most sublime emotionally, concise structurally and perfectly 'composed' pianistically of any Schubert work. It's a bit like looking at a chain of mountains in the Appalachians: the summits are different yet similar, look about the same height, are seen from the same distance and yet, one of them seems to tower above the others, not by virtue of sheer altitude, but its shape, height and mass just give it more presence. A very subjective impression, but it lingers and imposes itself to the conscience. To some that impression is left by D.960, to others by D. 894.
Chamber: again, obvious candidates are not exactly thin on the ground.
Brian's choice of D.956 is so brilliantly argued and
deeply felt that I find it hard not to concur. To me the Quintet is such an himalayan peak that it sheer mass and girth make it harder than many to grasp and absorb (if one can ever grasp and absorb that masterpiece's full musical greatness). The trios, the quartets in A and D minor: possibly.
In the end my choice will seem almost a cheat: no longer chamber, not yet orchestral: the
Octet in F, D.803. It is built in the olden form of the classical serenade or divertimento. In 6 movements, each having its own character, with no particular attempt to create or even simulate a classical structure. Yet each section tails off the preceding while offering a contrast of textures and timbres, a different rythmic feel. Melody reigns. In some works Schubert strained very hard at (and achieved !) a kind of moto perpetuo, rythmic and harmonic screws turned up one notch every 30 seconds (finales of symphonies 2, 4 and 9, quartet D. 810 or sonata 19 being cases in point). Nothing of the sort in the Octet. And yet the variety of writing never gives up. There is no sameness (remember Benvenuto Cellini !), no
ennui, never does the work seem to linger (Schumann famously spoke of Schubert's 'divine lengths', a notion that could be applied to the Quintet, the last sonata, the 9th symphony, Winterreise or the Octet).
The Octet combines the formidable structural girth of the Quintet, the
gemütlich melodic easiness of Der Hirtl auf dem Felsen, the dogged, pensive mien of the last sonata, the somber, minor key feelings of the last three sonatas and in the end, the triumph of good humour and the joy of basking in a sea of melodies of the 'Rosamunde' quartet.
True, the Octet is through and through a major mode composition, while so many of Schubert's greatest utterances are either in a minor mode, or explore the nether reaches of the harmonic world. Only Beethoven in his post op. 100 works would explore such uneasy realms. This composition belongs to the handful of 'free form' works that hark back to the concept of the Suite, Partita, Divertimento or Serenade, all of which are 'old' forms, whereas its harmonic language bespeaks of a new, liberated aesthetic, with an emphasis on expressing and releasing feelings. Schubert often alternated between 'feelings' ( as in Der Hirt or the Octet) and raw emotions (Die schöne Müllerin, the A major sonata, the D minor quartet). I don't think one can come to Schubert and choose. You have to take it all first, live with it for a few years and then settle in your own schubertian nest.