In the space and generous acoustics of the Panteão Nacional, the theme of Improbable Dialogues opposes contrasting musical styles and languages: Tchaikovsky and Rachmaninov, two prominent composers of great Russian music, with their dense polyphony; the British Byrd, Tallis, Weelkes and Purcell, and even Elgar and Holst, with their transparency and subtlety; and the German composer Johannes Brahms, with one of his greatest motets, a masterpiece of nineteenth-century choral music. In two moments, the vocal performance will be punctuated by pieces that explore the expressive and technical potential of the flute, with Amália Tortajada performing pieces by Nielsen and Varèse.