Praise be to Carl Nielsen. Praise always, of course, to one of the greatest symphonists, and happy 150^th birthday (again), but gratitude on this occasion is due to a programme mostly lining up Nielsen works rare and familiar, for getting me to the Albert Hall to witness a surely unsurpassable performance of the Brahms Violin Concerto.

Drawing an audience of five and a half thousand in to listen intently is harder than pushing out into the vasts of the Albert Hall. Yet it’s what seems to work best in this unpredictable space, and last night masterful veterans Elisabeth Leonskaja and Charles Dutoit knew exactly what to do. The results were romantic introspection in Mozart - an unfashionable but valid alternative to authentic sprightliness - and a Shostakovich Fifteenth Symphony that was more skull than skin, but a compellingly decorated skull for all that.

It was the first major casualty of the 2015 Edinburgh International Festival. Global superstar pianist Lang Lang was stuck overseas, forbidden from flying by his doctor because of an ear infection, and therefore unable to perform Bartók’s Second Piano Concerto with the Philharmonia Orchestra as planned (it had been an enticing prospect). But fear not, Lang Lang lovers – word is that he’ll be recovered in time for his solo recital of Bach, Chopin and Tchaikovsky on Friday 21 August.

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.

From Sakari Oramo’s riveting Nielsen symphonies at the Barbican to Thomas Dausgaard kicking off the Proms’ Sibelius cycle, the two Nordic immortals are well served in their 150th birthday year. The BBC Scottish Symphony Orchestra, whose reins Dausgaard takes over from the great Donald Runnicles in 2016, may not have the sheer heft of the Berlin Philharmonic strings we heard earlier this year in Rattle’s Sibelius. But the Glasgow-based players get much deeper under the skin, and prove so much lighter on their feet when the Danish conductor takes flight.

On paper it looked like it would be very much a concert of two halves. James MacMillan’s energetic, glittering Second Percussion Concerto was unveiled last year and received its first UK performance in London last December, and it was getting its premiere in the composer’s homeland at this Edinburgh International Festival concert from its dedicatee, percussionist Colin Currie, and the Royal Scottish National Orchestra. And in the second half, something entirely different: Sibelius’s rarely performed, hugely expansive choral symphony Kullervo.

Pairing Messiaen’s Turangalîla Symphony with John Foulds’ Three Mantras was a smart piece of programming: established modern classic and obscure novelty sharing an inspiration from Indian music and philosophy, and both perfectly designed for showing off a very fine orchestra to its best advantage.

The pulling power of the BBC Proms was in action last night, as a virtually full Royal Albert Hall settled down at 6.30pm, and braced itself for 22 testing minutes of restless, angular, unforgiving 1960s Boulez.The audience had been lured in by the gentler fare that was to come in the second half, but Boulez's Figures - Doubles - Prismes, under the taut control of its pulse by François-Xavier Roth, definitely left its mark.

Sir John Eliot Gardiner has made great play for years with the idea that Beethoven’s Fifth is a revolutionary symphony in not only musical but political terms. Accordingly the first bars were a call to arms, taking no heed of a restless Proms audience, or the Albert Hall’s generous acoustic, ploughing into and then through the argument with the joyful fury of a class war demo breaking police lines.