In November of 1779 a fire at Eszterháza, the lavish estate of Haydn's employer, Prince Nikolaus, destroyed the palace's opera house, and along with it Haydn's harpsichord and a number of important manuscripts. Despite this tragedy, just a month after the fire a cornerstone was laid for a new and grander opera house. It was for this ceremony that Haydn composed and first performed his Symphony No. 70.

Haydn had diminished his symphonic output during the preceding decade, concentrating instead on other genres. Most of the symphonies he did compose were in full or in part reworkings of incidental music; the D major symphony heard this afternoon is the notable exception: while it overflows with wit and good cheer throughout, it exhibits a contrapuntal mastery and a seriousness of artistic purpose unmatched by its contemporaries in Haydn's catalog.

The symphony begins explosively with a descending D major triad, in a fast 3/4 time signature. Nearly all of the movement is derived from these opening bars and from an insistent rhythm of four repeated notes—this rhythm concludes the first half of the movement (on a unison A) and are answered in startling fashion by four C-natural unisons to open the second half.

Haydn dubbed the slow movement specie d'un canone in contrapunto doppio, or a two-part canon in which the two parts of the canon are invertible. The movement alternates between minor and major, variations of the themes passing around the orchestra. The movement concludes in D minor, although there is no third in the final chord, allowing the delightful minuet to return the work to D major. After a graceful trio, there is the customary repeat of the minuet, but Haydn tacks on a coda of grander scope to finish off the movement in powerful fashion.

The finale returns to D minor (not unprecedented, but still quite unusual at the time), beginning with five repeated unison notes, all D (just like the Beethoven violin concerto on the first half of this program). Haydn's rhythm, an extension of the four repeated notes from the first movement, is at first answered by gentle rising and falling string phrases. Before long, however, Haydn is once again flexing his contrapuntal muscles, as the first four notes of this rhythm launch a fugue—and not just any fugue but a triple fugue in contrapunto doppio, or three simultaneous two-part fugues.