These two pieces, only ten years apart (the Brahms written first, in 1877), are pretty characteristic of their composers' mature styles. Tchaikovsky is very much more at ease writing for orchestra. For a pianist, his string writing is surprisingly natural. There are none of the horrible meandering string-crossing figures with which Brahms unwittingly torments the violins, and you don't get the occasional sense that this is piano music arranged for larger forces (the clarinet arpeggios that erupt out of nowhere a minute or so into the last movement of the 2nd Symphony are a particularly egregious example of this, but there are many others).
Both composers write wonderfully for horns (the solo in the Tchaikovsky slow movement every bit as good as the coda of the Brahms first movement), and for solo woodwind generally, but taken as a whole Brahms' ensemble wind writing has the edge: Tchaikovsky is a perfectly good functional wind writer, and woodwind solos like the flute solo in the slow movement of the 1st Piano Concerto need no apology, but the way Brahms combines woodwind and horns has that extra sparkle based on a total understanding of sonorities which Tchaikovsky perhaps never quite attains.
So far so marginal. The real differences lie in the substance of the music. Brahms' symphonies are often built from tiny thematic fragments which saturate them from start to finish (a technique brought to the highest pitch of perfection by Sibelius); Tchaikovsky's construction is much looser and more pedestrian. But again, these are differences for anoraks. What about the music's heart?
Brahms has often been criticised for his emotional reticence; Tchaikovsky famously called him a "talentless bastard", and Britten once said that he played some Brahms once a year just to remind himself how bad it was (a remark which surely says much more about Britten than it does about Brahms). It's true that Brahms often makes an idea fold back on itself just as it threatens to get out of hand, whereas Tchaikovsky, a master of the sustained orchestral climax, likes nothing better than to cut loose; you can imagine him grinding his teeth at Brahms self-restraint. And yet I find that, for all his reticence, there is an emotional honesty to Brahms which, in his symphonies, Tchaikovsky attains only with the Pathetique. Elsewhere his raucous finales have a hollow ring; in fact one of the great constructive strokes of the Pathetique is the placing of a raucous march third, a movement which sounds like one of Tchaikovsky's bad symphonic finales until one hears the terrifyingly naked music which follows in the last movement. Was there ever a more brilliantly damning criticism by a composer of his own method?
On an altogether more mundane level the climax of the 5th, in which the motto theme of the opening is switched from minor to major, feels too pat a solution to the difficulties of the opening three movements; besides, the material simply isn't good enough in the major.
Psychologically, I find Tchaikovsky curiously simple. Although things are generally either good or bad, even the good times seem too good to be true; even his wonderful light music is only a step away from heartache. Brahms is much more enigmatic. You might begin by saying that Brahms is only a step away from - and then there would be a long pause because there is no obvious end to the sentence. But Brahms' restraint, however difficult to pin down, has the priceless advantage that it compels the listener to engage all the more closely for having suggested that there might be things going on that are not explicitly stated. I have been fortunate enough to conduct all the Brahms symphonies bar the 3rd (the Cinderella of the set) several times, and for me they are all totally convincing, in terms of material, psychology and pacing. Never do the upbeat finales of Tchaikovsky 4 and 5 ring true in the same way. Tchaikovsky never seems to address the depths of despair the earlier music expresses with such harrowing clarity. The triumph comes unearned, and might just as well be from a different planet.
All Brahms' symphonies come to a resolution which seems to be a consequence of everything that has come before. The 1st symphony is, famously, an object lesson in how to solve the problem of the symphonic finale: misery squarely confronted and overcome. The 4th faces death with a wintry magnificence. The 3rd subsides in stoic acceptance. Even in the 2nd, a much happier work on the whole, the last movement is no empty parade. Technically a sonata-rondo without a great deal in the way of darker moments, one feels as if in the eye of a D major whirlwind, occasionally experiencing the outer fringes of a tumultuous updraft but in the last few pages whipped up by the storm and carried away in a joyful buoyancy.
