A major
There are not as many symphonies in A major as in D major or G major, but more than other sharp keys. Beethoven's Symphony No. 7, Bruckner's Symphony No. 6 and Mendelssohn's Symphony No. 4 are almost all the symphonies in this key in the Romantic era. Mozart's Clarinet Concerto and Clarinet Quintet are both in A major. Mozart used clarinets in A major often.