B-Flat Major
(Ger. B dur). If any key can claim to be the key of the universe, it is B♭ major. The transposing instruments of the orchestra, particularly trumpets and clarinets, are most often in B♭. This tuning enables them to be played in the key of B♭ major with the same ease that pianists play in C major.
Because natural trumpets are tuned to B♭ major, it is the key of fanfares and of festival and military marches. The march of the soldiers in CHARLES GOUNOD'S FAUST, the return of Radames from the conquest of Ethiopia in GIUSEPPE VERDI's AIDA, the march of the children and the signal call summoning Don José back to the barracks in GEORGES BIZET's CARMEN, and the dramatic trumpet call in LUDWIG VAN BEETHOVEN's FIDELIO, announcing the arrival of the governor, are all in B♭ major.
Standard arrangements of national anthems, including The Star-Spangled Banner and the Marseillaise, are in B♭ major. GEORGE M. COHAN'S song Over There, imitating the bugle calls of the doughboys of World War I, is in B♭ major, as is the bugle call that announces the opening of horse races. And then there is that gloriously uninhibited upward sweep of the clarinet (a B♭ clarinet, of course) that opens GEORGE GERSHWIN'S Rhapsody in Blue.
