The Berlin Philharmonic are in London tonight and tomorrow at the Proms, days after closing the Edinburgh international festival in thrilling style. It was their first visit to Scotland in over 20 years, but the orchestra and their chief conductor, Kirill Petrenko, are regular Proms visitors; their Royal Albert Hall concerts are always season highlights.“The best orchestra in the world”, as it is often hailed, brings programmes that offer the expected and – for them – the unexpected. Tonight there’s Tchaikovsky’s Fourth Symphony paired with Elgar’s Enigma Variations, a piece that’s still an astoundingly rare visitor to this orchestra’s concerts;...