The Symphony No. 51 in B♭ major, Hoboken I/51, is a symphony by Joseph Haydn, written in either 1773 or 1774, [1] although the exact dating remains ambiguous. [2]
Scored for 2 oboes, 2 horns (B♭ alto, E♭), bassoon and strings. The work is in four movements:
Sometimes described as "a concertante piece featuring the two horns, which are given parts of staggering difficulty." [3] The second, slow, movement contains high notes for the first horn (including a written F6 for horn in E♭) and very low notes for the second horn. [4] The third movement contains an even higher note for horn, a written C6 for horn in B♭ alto (sounding as B♭5), one of the highest notes ever written for horn. Heartz has noted the character of the fourth movement as reminiscent of the French rondeau. [2] The first contrasting section is an oboe solo in E♭ major and the second contrasting section is fortissimo and in G minor. [4]