Osmo Vänskä isn't by any means the only Finn who conducts magnificent Sibelius. Sakari Oramo is the BBC Symphony Orchestra's property, but the London Philharmonic could have gone for a change and invited Vänskä's equally impressive and even more experienced successor at the Lahti Symphony Orchestra, Okko Kamu. Still, they played safe by repeating their success with this combination in 2010, adding British string concertos, and why not?

2015, Sibelius anniversary year, yielded no London performances of the composer's last masterpiece, the Prospero's farewell of his incidental music to The Tempest. With Shakespeare400, 2016 has already made amends: even if the Bardic input came solely from Simon Callow doing all the voices, and summing up the plot – "elsewhere on the island", "meanwhile..." – Osmo Vänskä served up more of the original numbers for the 1926 Copenhagen production than I've encountered live before.

Questions of what is authentic and what is retro get more complicated the more the information economy matures. Music from decades past that only tens or hundreds of people heard at the time it was made becomes readily available, gets sampled by new musicians, and passes into the current vernacular. Modern musicians play archaic styles day in day out until it becomes so worn into their musculature that it reflects their natural way of being. Tiny snippets of time that were once meaningless become memes that are shared and snared into the post-post-modern digital tangle.

Is language a barrier to international recognition? Is English necessary to make waves worldwide? Musicians from the African continent and South America regularly perform in their native tongue beyond the borders of their home countries. But often they are – rightly or wrongly – marketed or pigeon-holed as world music, a branding which allows for eschewing the Anglophone. The always problematic label of world music can be and is debated endlessly, but one thing is certain: for Scandinavia, most internationally successful music is delivered in English.

When Lahti’s Sibelius Hall finally shone and coruscated into life in 2000, the 100,000 citizens of this modest Finnish town, not to mention acousticians from all over the world, could hardly believe their eyes and ears. Here, at last, was not only a top concert hall fit for what had already become a world-class orchestra under notable Sibelian Osmo Vänskä, but also a twofold architectural wonder.

Nearly 10 years ago to the day, an almost unknown 24-year-old Venezuelan conductor came a cropper when valiantly stepping in at short notice to conduct Sibelius’s Fifth Symphony at the Proms. (His name was Gustavo Dudamel. Whatever happened to him?) To pull off successful performances of Sibelius’s seven symphonies you need not just the ability to fire up players but the intellectual grasp to grip their elusive, fluid structures.

A second night of Sibelius symphonies at the Proms, packed to the rafters just like its predecessor. Exit Thomas Dausgaard, the tuba needed for the first two symphonies but not for the Third or – surprising given its pervasive darkness – the Fourth, and the air that had billowed around supremely supple performances. Enter Ilan Volkov to bring too much dark earth and inorganic point-making at first, though the BBC Scottish Symphony Orchestra, its strings sounding tougher if less inward from a different point in the hall, was still on world-class form.