Così dunque tradisci K.432

Another of Mozart’s favourite singers was the bass Ludwig Fischer, who created the role of Osmin in Die Entführung aus dem Serail in 1782. A year later he was singing in Bernasconi’s Temistocle and, feeling perhaps that the score offered him little scope to show off his famously wide range – he was said to have “the depth of a cello and the natural height of a tenor” – asked Mozart for a new version of one of his arias. Mozart duly obliged with a recitative (“Così dunque tradisci”) and aria (“Aspri rimorsi atroci”) which not ony adhere to Bernasconi’s opera seria style but also supply a vocal line covering two octaves, its top note approached by a spectacular leap (on “Ch’or mi sgridate”) its bottom note touched on at the very end.