Although the four days of Norway’s 15th by:Larm Festival were dominated by the presentation of the second annual Nordic Music Prize, there were plenty of other distractions: a sobering tour of Norwegian black metal’s infamous sites, a talk by legendary Nigerian drummer Tony Allen, what felt like millions of shows in millions of venues, and weather confounding all expectations of what Oslo ought to be like in February.

The surprises linger longest. The things you’re not prepared for, the things of which you’ve got little foreknowledge. Lykke Li’s Wounded Rhymes was amazing, and she was equally astonishing live, too. Fleet Foxes's Helplessness Blues was more than a consolidation on their debut and The War On Drugs’s Slave Ambient was a masterpiece. But you already knew to keep an eye on these three. Things arriving by stealth had the greatest impact.

Is it ever a good idea to programme two symphonies by one composer in a single concert? Maverick Valery Gergiev is likely to stand alone in applying the rule to Mahler. Yet curiously his Prom marathon of two big instalments made more sense as stages on a journey than yoking together the outwardly less time-consuming symphonic adventures of Sibelius. Jukka-Pekka Saraste's attempt last night to run the opposing approaches of the last two Sibelius symphonies head to head worked no better than usual.

The rest, it seems, is not to remain quite silence from the 32 years Jean Sibelius lived on after completing his last major work, the astonishing incidental music for a production of The Tempest in 1925.

It’s pronounced doh, like Homer Simpson’s favourite exclamation. Although The dø aren’t yellow cartoon characters, they edge towards the caricature with songs like “Gonna be Sick!” and “Smash Them All (Night Visitors)”. Their art pop has a slight taste of The Sugarcubes and Olivia Merilahti’s vocals can be a bit too cutesy-pie. But Both Ways Open Jaws is great.

With Riccardo Chailly's Leipzig Beethoven series well into its capacious stride, another cycle of symphonies keeping unusual company begins. This one featuring the BBC Symphony Orchestra will take longer and features six conductors, four of them known masters of their subject, chimerical Sibelius. The only problem last night was that Sakari Oramo, in tandem with his charismatic soprano wife Anu Komsi, took us to such strange and wonderful places in the first concert that I want them both back for the next five.

Isn’t it strange how national talent goes by subject? Put on a blockbuster exhibition of Dutch painting and the queue will stretch to the Embankment. But can you imagine a festival of Dutch music? Sweelinck (d 1652) and Andriessen (b 1939) more or less sums it up. The BBC brought together three living Dutch composers for this Portrait concert, and one of them wasn’t after all Dutch (“I’ve kept my Swedish passport,” he insisted rather unchivalrously in the pre-concert interview).

Iceland is remote. Strategic too. Vikings stopped off there on the way to North America. It hosted the Reagan-Gorbachev summit 25 years ago. On the anniversary, visitors from America, Canada and across continental Europe are in Reykjavík for the 13th annual Iceland Airwaves. Over its five days the festival brings an extraordinary range of music to Iceland’s capital. Three years on from the country’s financial meltdown, Iceland remains strategic. Culturally strategic.

It’s almost dark. Frescoes depicting the cycle of life are barely visible. They could be shadows. Waves of sound pulse through the mausoleum of Norwegian artist Emanuel Vigeland. Fiddle player Nils Økland is feeding the 15-second delay with peals that reverberate around the space, folding back into themselves. It’s a spooky, unforgettable introduction to FolkeLarm, Oslo’s annual festival of Nordic folk music.

It’s pretty damn cold inside the Arctic Circle, but Eric Bana’s former CIA agent Erik Heller doesn’t notice. Striding out of his wilderness cabin into metres-deep snow, he’s fine in a business suit. Demanding a catering-sized suspension of disbelief, Hanna is - as ludicrous thrillers go - pretty special.