There is an argument to be had as to how many symphonies Josef Haydn wrote. There are 104 numbered symphonies but Anthony von Hoboken, who catalogued Haydn’s works and broke them down into categories, included a few other works in the “symphony” category, notably two works known as Symphony A and Symphony B and a Sinfonia Concertante in Bb, for violin, cello, oboe, bassoon and orchestra. It was composed in England in 1792, during the period when Haydn was working on the late symphonies known as the London Symphonies.
A sinfonia concertante is essentially a cross between a concerto (usually for one soloist and orchestra) and a symphony (usually for orchestra alone). It employs two or more soloists and resembles the Baroque form, the concerto grosso. Several of my favourite Haydn symphonies include strong concertante elements (for example, No. 6 and No. 31, which I included in earlier posts). I was not at all surprised to find myself drawn to this work and to find myself listening to it again and again. Hoboken had the right idea, I think. As for how many symphonies Haydn wrote, does it matter? Do you include the single movement often used as an overture to The Fisherwomen? Lists of symphonies by Schubert and Borodin include incomplete, two-movement works. It’s a bit like counting the planets. Should Pluto have been demoted? How many rocks of a similar size are out there?