The Symphony No. 98 in B♭ major, Hoboken I/98, is the sixth of the twelve London symphonies (numbers 93–104) composed by Joseph Haydn. It was completed in 1792 as part of the set of symphonies composed on his first trip to London. It was first performed at the Hanover Square Rooms in London on 2 March 1792.
Haydn composed the symphony in early 1792. At the time, Haydn was in the midst of the first of his two visits to London, under contract to perform a series of new symphonies with an orchestra led by Johann Peter Salomon as concertmaster. The symphony was performed on 2 March 1792 at the Hanover Square Rooms, with Haydn directing the orchestra from the keyboard. The premiere came two weeks after that of the Symphony No. 93, and one week before that of the Sinfonia Concertante. Haydn recalled that at the premiere of the No. 98, the first and fourth movements were encored.
The work is scored for one flute, two oboes, two bassoons, two horns, two trumpets, timpani, strings and cembalo. At the symphony’s premiere, Haydn likely played the cembalo part on a fortepiano, but in many modern performances the part is played on a harpsichord, which is what the German word cembalo means. The cembalo part is only scored for a brief solo in the fourth movement, but Haydn would have conducted the premiere sitting at the keyboard and probably used it in a continuo role throughout the whole of the symphony.