The move from the Baroque concertos of Bach and Handel to the Classical concertante works of the likes of Haydn and Mozart involved considerable change. Counterpoint now took a lesser role as composers favoured the more straightforward – and easily assimilated – melody and accompaniment. Focus moved from polyphonic to homophonic textures with much of the drama being played out through the contrast of keys in sonata form.
The term ‘sonata’ is a rather confusing one, since it can be applied to an entire instrumental work (normally in three movements, fast – slow – fast) or to the internal layout of a single movement when it becomes known as ‘sonata form’. The influence of this formal procedure on the concerto was considerable. First movements no longer started with brief ritornellos (they managed to hang on to shelf life by transforming themselves into last movement rondos) but with orchestral expositions of the material on which the entire movement was to be based, known as the ‘opening tutti’ which was followed by the (frequently dramatic) entry of the soloist playing the orchestral material again, but in a more elaborate and decorated form – this, standard sonata form procedure is known as a double exposition.
The concerto grosso was going through the additional trauma of metamorphosing from its baroque format (a fine example of that below) and forming an alliance with the new-fangled symphony to become the sinfonia concertante…
… the sinfonia concertante.
An example of the ‘classical’ concerto with its sonata form first movement. (I find the soloist a bit overly histrionic, but his playing, I think, makes makes the performance worthwhile.)