A-flat major
Edward Elgar's Symphony No. 1 in A-flat major is probably the best-known symphony in that key. Arnold Bax's last symphony is also in the same key. A-flat major is the major key with the most flats that Domenico Scarlatti used in his keyboard sonatas, though he used it only twice– in K. 127 and K. 130. Felix Mendelssohn and John Field each wrote one piano concerto in A-flat.