The Symphony No. 51 in B-flat major, Hoboken I/51, is a symphony by Joseph Haydn

Joseph Haydn

Franz Joseph Haydn , known as Joseph Haydn , was an Austrian composer, one of the most prolific and prominent composers of the Classical period. He is often called the "Father of the Symphony" and "Father of the String Quartet" because of his important contributions to these forms...

, written in either 1773 or 1774, although the exact dating remains ambiguous.

Scored for 2 oboe

Oboe

The oboe is a double reed musical instrument of the woodwind family. In English, prior to 1770, the instrument was called "hautbois" , "hoboy", or "French hoboy". The spelling "oboe" was adopted into English ca...

s, 2 horn

Horn (instrument)

The horn is a brass instrument consisting of about of tubing wrapped into a coil with a flared bell. A musician who plays the horn is called a horn player ....

s (B flat alto, E flat), bassoon

Bassoon

The bassoon is a woodwind instrument in the double reed family that typically plays music written in the bass and tenor registers, and occasionally higher. Appearing in its modern form in the 19th century, the bassoon figures prominently in orchestral, concert band and chamber music literature...

 and strings, The work is in four movements:

1. Vivace, 3/4
2. Adagio
3. Menuetto
   Minuet
   A minuet, also spelled menuet, is a social dance of French origin for two people, usually in 3/4 time. The word was adapted from Italian minuetto and French menuet, and may have been from French menu meaning slender, small, referring to the very small steps, or from the early 17th-century popular...
   
    - Trio I - Trio II, 3/4
4. Allegro

Sometimes described as "a concertante piece featuring the two horns, which are given parts of staggering difficulty." The slow second movement contains high notes for the first horn (including an f which is considered the highest note ever written for the horn) and very low notes for the second horn. Heartz has noted the character of the fourth movement as reminiscent of the French rondeau. The first contrasting section is an oboe solo in E-flat major and the second contrasting section is fortissimo and in G minor

G minor

G minor is a minor scale based on G, consisting of the pitches G, A, B, C, D, E, and F. For the harmonic minor scale, the F is raised to F. Its relative major is B-flat major, and its parallel major is G major....

.