Today, Luxembourg celebrates its national holiday. For decades, this day has been marked by cherished traditions: fireworks, a military parade and a solemn mass with an even more solemn Te Deum. Lully, Bach, Händel, Haydn, Mozart, Mendelssohn, Berlioz, Kodaly, Britten… many composers have set this early Christian hymn of praise to music. But one of the most impressive versions I know has been written by the Estonian composer Arvo Pärt, who turned 80 last year. I have a wonderful record released by the German label ECM recorded by the Estonian Philharmonic Chamber Choir and the Tallinn Chamber Orchestra conducted by Tonu Kaljuste.