Joseph Haydn's Symphony 'A' in B♭ major, Hoboken I/107, was written between 1757 and 1760. It is not in the usual numbering scheme for Haydn symphonies because it was originally thought to be a string quartet (Op. 1/5) and was catalogued as Hob. III/5.
It is scored for 2 oboes, bassoon, 2 horns in B♭ alto, strings and continuo.