Young Amadeus is growing up in real time with MOZART 250, Classical Opera's ambitious 26-year project following its hero's creative life from childhood to the grave. 2015's start, marking two and a half centuries since the boy wonder's first visit to London, and its sequel had little to show of its main man, but plenty of other, senior composers flourishing in the same years.

Fiftysomething may well be the new 32, the age Strauss and Hofmannsthal made the central figure of the Marschallin in their "comedy for music" Der Rosenkavalier. Hearts and minds no doubt still move with Renée Fleming, senior doyenne of the role in Robert Carsen's Royal Opera production, but she is mirroring her character in bowing out gracefully to the next generation, and fellow American Rachel Willis-Sørensen is clearly the new Princess Werdenberg on the Viennese block.

Ebullient, prolific, loquacious and a charmingly enthusiastic historian both in print and for television, Simon Sebag Montefiore has turned his attention to the pivotal city of Vienna, nourished equally by the Danube and its central geographical position in Europe.

Superior light music with a sting, done at the highest level: what could be better for a summer lunchtime in the light and airy Cadogan Hall? Our curator was that most collegial of top soloists, trumpeter Håkan Hardenberger. He'd invited colleagues of many nations, all of them first rate, but it was almost a given that chansonnier-composer HK Gruber would steal the show.

Recently the television historian Bettany Hughes, bright-eyed, bushy-tailed, energetic, enthusiastic and rather astonished, has tramped across the continents on our behalf, making a clutch of hour-long documentary introductions to the individuals with the most profound influence on human society. For this third and final film (made in association with the Religion and Ethics department of the Open University), she had as her quarry the medical man whose insights, however intuitive rather than scientific in the modern sense, formed and still form our view of ourselves.

Who wouldn't wish to have been a fly on the wall during those pre-recording days when composers and their friends played piano-duet arrangements of the great orchestral works? Any notion that we don't need such reductions anymore was swept aside by Antoine Françoise and Robin Green in the fourth concert of an untrumpeted but brilliantly conceived piano-duo series matching transcriptions of 20th-century Viennese masterworks with Mozart and/or Schubert and five world premieres.

2016 began with the passing of Pierre Boulez, arguably the doyen of modernism in the field of classical music. Now, only a couple of months later, it is the turn of Nikolaus Harnoncourt, a musician occupying a similar level of singular elevation but this time in what is often described (certainly inadequately in this case) as the "period instrument" movement.

Last night's perfectly-judged, superbly communicated performance of Mahler's Fourth Symphony served as a reminder that the passion, experience and astonishing musicality of 86-year-old conductor Bernard Haitink are things to be cherished and never taken for granted. The symphony, first performed in 1901, was the main work in this second of Haitink's three concerts with the LSO before they leave together for Japan.

Antonio Salieri. Mozart’s nemesis – wrong. Beethoven’s teacher – right. Unjustly neglected in his own right – maybe. Bampton Opera have put some flesh on the bones of his reputation with an English-language production of La grotto di Trifonio, first performed in Vienna, October 1785. They have done Salieri proud: we can see for ourselves why he is who he is.

Every Proms season needs a late-romantic rarity to envelop its audience in a bewitching spider-web of sound. This year’s candidate was of more than passing interest, the incandescent Second Symphony of Franz Schmidt, scion of the Austrian Empire – born in what is now Bratislava, three-quarters Hungarian, an embattled cellist in the Vienna Philharmonic during Mahler’s tenure. The orchestra now wants to do him proud again, thanks to the very centred championship of Semyon Bychkov. And Schmidt’s music has the virtue of not being over-familiar to the Viennese players, unlike Brahms’s.