Tradition and vision, young and old, grand spectacle and intimacy, existentialism and commitment: this year’s Salzburg Mozart Week offered the requiem of its namesake in two versions that couldn’t be further apart, although both were based on the same score. The 81-year-old conducted once Jordy Savall with his chamber orchestra Le Concert de Nations and the small choir La Capella Nacional de Catalunya a version that shatteringly emphasizes the terror of death; Four days later, the 30-year-old conductor Thomas Guggeis, once again standing in for Daniel Barenboim, who was ill, offered a traditionally binding reading with the large-scale Vienna Philharmonic and the Wiener Singverein, which performed in mega strength.