As the first example of a “mass art”, Wagner’s operas are portrayed as a forerunner to David Bowie and gangster rap, promoting a “terrorist function” of music that breaks down the boundaries between high and low culture.
Wagner’s crucial role in the thinking of Nietzsche, Adorno and Heidegger leads Badiou to posit the composer as the “litmus test” for the role of music in philosophy. Whilst these philosophers tended to criticize Wagner’s attempt to marry nationalism and art as “proto-fascist”, Badiou vigorously defends the positive energy of Wagner’s “enthralling, alluring, deceptive, hysterical, shimmering, seductive, sexual musical edifice.”
More: Here
PS: this was selected as Paul Griffiths book of the year (2010) in The Times Literary Supplement. He said:
Not wearily, but freshly and brightly, Alain Badiou takes up from Nietzsche, Adorno and Lacoue-Labarthe the philosophers' debate with the old magician of Bayreuth in his Five Lessons on Wagner (Verso). Badiou's is an un-Wagnerian Wagner, a composer of ambiguities and silences, of suffering and (his own word) heartbreak a composer still with lessons for the music of today.