Page "Classical period (music)" Paragraph 34

When Haydn and Mozart began composing, symphonies were played as single movements — before, between, or as interludes within other works — and many of them lasted only ten or twelve minutes ; instrumental groups had varying standards of playing, and the continuo was a central part of music-making.

In the intervening years, the social world of music had seen dramatic changes: international publication and touring had grown explosively, concert societies were beginning to be formed, notation had been made more specific, more descriptive, and schematics for works had been simplified ( yet became more varied in their exact working out ).

In 1790, just before Mozart's death, with his reputation spreading rapidly, Haydn was poised for a series of successes, notably his late oratorios and " London " symphonies.

Composers in Paris, Rome, and all over Germany turned to Haydn and Mozart for their ideas on form.