“You’re a little dull/ My dear Pompeo/The ways of the world/Go study them”. The words of the aria, “Un bacio di mano” (“A kiss on the hand”), composed as an insert for Pasquale Anfossi’s opera Le gelosie fortunate by Mozart in 1788, to words probably by Lorenzo da Ponte. And what, pray, has that got to do with Mozart’s C Major Symphony K551, known since the early 19th century as the “Jupiter”? Well, rather a lot, actually: the music that accompanies those words in the aria also makes a cheeky and unexpected appearance just before the end of the first section of the first movement. This is a self-quotation that’s completely unnecessary according to the tonal and harmonic drama of the symphony so far. Mozart has got himself into the right key, he’s done all the hard work of modulating from C major to G major, and he’s already written one of the most memorable first sections to a symphony that anyone had conceived up to this point, the summer of 1788. So why risk interpolating yet another tune into the concatenation of ideas that he’s already given his listeners, and asked his orchestra to dramatise; and a melody, what’s more, that comes from a different expressive world, the low comedy of opera buffa as opposed to high-minded symphonic discussion? Mozart puts the whole structure of this movement on the line, seemingly for the sake of a compositional joke. It’s a piece of postmodernism avant la lettre, and the kind of thing that Beethoven, for all his iconoclasm, hardly risked in the same way in his symphonies.

This musical intervention is usually passed over in the way the symphony is performed and heard today. It’s as if this music has become too familiar, so we don’t often hear what I think the Jupiter symphony is really about. For me, this C major symphony is written at the furthest edges of the possible for Mozart, in terms of seeing just how many different expressive and compositional contrasts he can cram into a single symphony. And he’s not doing that for the sake of reconciling these opposites or to create a greater unity (the kind of thing that we like to imagine Mozart was up to, because we prefer to think of him as a romantic idealist rather than an 18th century humanist). Rather, I think he’s trying to achieve a complexity of emotional experience and richness of invention that is poised – sometimes on this side, sometimes on the other! – of a musical cliff-edge of coherence. A bit like the mixed metaphors of that sentence; what I mean is that this is a symphony of extremes, something that’s symbolised in the juxtaposition of the martial and the plangent in the two ideas you hear in the symphony’s very first four bars (Nikolaus Harnoncourt dramatises that initial collision best of all in his recording.)

But back to that interpolatory opera buffa melody: listen to what René Jacobs does in his performance with the Freiburg Baroque Orchestra, slowing the music right down to force you to be conscious of how weird this moment actually is, before speeding up to the “correct” tempo. In fact, Jacobs is only restoring the tune to the speed you would hear the melody at when it’s sung as an aria, making us aware that something from another world has landed in the world of the symphony. And Mozart’s secret is only revealed after you’ve heard the repeat of the first section. In the central part of the movement, this innocent little tune is exposed to all of the contrapuntal experience Mozart can muster, so instead of opera buffa, the tune is forced into a crucible of highfalutin compositional mastery and chromatic intensity. It’s a fulfilment of the prophecy of the words that originally accompany this music in Anfossi’s opera (they’re initially a warning about the fickleness of beautiful women, a trope of 18th century operatic stories); an exhortation to “study” and to be immersed in the “ways of the world”. It’s an intertextual gag of the highest musical and dramatic subtlety.



And that kind of compositional and expressive high-wire act is what defines this symphony, all the way through. There isn’t time or space here to wax lyrical about the expanded song-form of the slow movement - among the most achingly sensual pieces of instrumental music that Mozart ever wrote, and certainly the most precipitously emotionally ambiguous slow movement in his symphonies; or to expound upon how the chromatic descent of the opening tune of the Menuetto is a transformation of an idea you’ve heard in the first movement (the second main melody of the Allegro vivace, since you ask), or how the trio section is an artfully artless prefiguration of the main motif of the finale.

However, I do have to tell you about that final movement. Famously, this Molto Allegro fuses sonata form with fugue; that’s to say, it fuses the high-watermark of late 18th century practice in instrumental music with the most prestigious, and most compositionally involved, form of counterpoint in earlier music: the fugues of the Baroque, like those by Bach and Handel, that Mozart knew and loved. But that’s not, in itself, an original idea – and neither is the four-note melodic tag (C-D-F-E) that is catalyst for this explosion of contrapuntal mastery. Mozart borrowed his supposed symphonic innovation from the Haydn brothers, Joseph (the famous one) and Michael (less famous, but equally influential on Mozart). We know that Mozart wanted to hear the latest fugues from Michael’s symphonies, which were written in Salzburg, and he asked his father to send them to him. That means he would have known the finale of Michael’s 28th Symphony, with its obsessive fugato, also in C major; probably the fugue that crowns his 34th, in E flat major; and quite possibly another fugue-finale from his 39th symphony, also in C major, composed just a few months before Mozart’s. The similarities between Michael’s 29th and 39th, and Mozart’s 41st are sometimes startling, as you can hear. Even more shocking, have a listen to this, the final movement of Joseph’s 13th Symphony, written in 1764. There’s the very same four-note idea used as the basis of a contrapuntal work-out of a symphonic finale. There ain’t nothing so old – or so new – as a fugato-style finale.

And that four-note motif has a history, and not just in Mozart’s own music (you can hear it most clearly in the Credo of his Missa Brevis K192, and in his 1st and 33rd Symphonies) and that of his contemporaries. In fact, it goes back to a 13th-century hymn attributed to Thomas of Aquinas, Pange Lingua, which Josquin des Prez used as the basis for probably his last Mass setting in 1515. Since then, the four-note melody at the start of the third line of the original hymn (which Josquin employs as a contrapuntal catalyst in his Kyrie) has turned up throughout musical history, especially as a fugal inspiration. That includes its use by Johannes Fux, the 17th and 18th century composer and theorist, in his famous textbook of musical polyphony Gradus ad Parnassum (which Mozart knew, and used in his own teaching of his English pupil, Thomas Attwood).

Which all means that Mozart’s composition of the finale of the Jupiter Symphony is a palimpsest on music history as well as his own. As a musical achievement, its most obvious predecessor is really the fugal finale of his G major String Quartet K387, but this symphonic finale trumps even that piece in its scale and ambition. If the story of that operatic tune first movement is to turn instinctive emotion into contrapuntal experience, the finale does exactly the reverse, transmuting the most complex arts of compositional craft into pure, exhilarating feeling. Its models in Michael and Joseph Haydn are unquestionable, but Mozart simultaneously pays homage to them – and transcends them. Now that’s what I call real originality.

Five key recordings

Freiburg Baroque Orchestra/René Jacobs: music-making that restores the shock of the new to Mozart’s symphony. Quite right, too.

Chamber Orchestra of Europe/Nikolaus Harnoncourt: Harnoncourt is scarcely less imaginative than Jacobs, and finds details in the part-writing of the finale that no-one else reveals.

Royal Philharmonic Orchestra/Thomas Beecham: OK, so Beecham doesn’t do the repeats, as he should do, but the warmth and subtlety of his Mozart are second to none.

Scottish Chamber Orchestra/Charles Mackerras: unfailingly satisfying symphonic logic from Mackerras and the SCO.

Staatskapelle Berlin/Richard Strauss: irresistible wildness (the speed, and the variation of tempo, in the finale!) and lucidity in Strauss’s 1926 performance, and some astonishing playing.