It’s been a quarter millennium since the birth of a certain scowling genius composer in the city of Bonn, and the music world is paying due note. Of uncounted traversals of Beethoven’s monumental 32 piano sonatas this year, few are likely to touch that of Igor Levit, an artist of towering motor skills, imagination, intellect, and focus. Not that he needs anyone to raise the stakes, but the fabled sophistication of the Salzburg audience can have that effect. —M.G.