The popularity of the concerto grosso faded after the Baroque era. However, the solo concerto soldiered on, remaining a vital musical force to this day.
What is a Concerto?
Classical composers took the vestiges of the Baroque solo concerto and expanded it into a three-movement tour de force for virtuoso instrumental soloist and orchestra. The solo part spotlights the skills of the performer and possibilities of the instrument. In the best concertos, there is a dialogue between soloist and orchestra, with both participants on equal footing.
Wolfgang Amadeus Mozart wrote Piano Concerto No. 23 in A major K. 488 in 1786. He was at the top of his game and his opera, Le nozze di Figaro, premiered the same year. This concerto is scored for piano, flute, two clarinets, two bassoons, two horns and a full string section.
Concertos share formal structures with the symphony. But, instead of four movements, the concerto normally features three movements in a fast-slow-fast tempo scheme. Like the symphony, the first movement is in sonata form. The slow and lyrical second movement uses various forms, but Mozart used ternary form (ABA) for Piano Concerto No. 23. Finally, the third movement is typically a fast paced rondo or sonata rondo form. In this case, Mozart choose rondo form.
The first movement of Piano Concert No. 23 uses the ubiquitous sonata form but with a twist: a double exposition. The first exposition is played by the orchestra while the soloist waits patiently. When the exposition repeats, the soloist enters. However, the repeat is not exact: modulations were added to increase tension and the piano embellishes the themes. Here's a breakdown of the double exposition sonata form used in Piano Concerto No. 23:
Exposition (A)
00:00 First theme in tonic key (orchestra only)
00:36 Transition theme
00:59 Second theme
Codetta and cadence
Exposition Repeat (A')
02:10 First theme in tonic key (piano and orchestra)
02:40 Transition theme and modulation to new key
03:10 Second theme in new key
Codetta and cadence in key of second theme
Development (B)
04:38 Development theme introduced
Development of themes and motives (piano and orchestra)
Modulations to new keys
Transition to recapitulation
Recapitulation (A'')
06:23 First theme in tonic key
06:52 Transition theme
07:21 Second theme in tonic key
09:36 Cadenza (piano solo)
10:40 Coda in tonic key
Before listening to the concerto, familiarize yourself with the themes. Mozart often bends the rules and his sonata form usually has something extra. In this case, two extra themes! The first theme is presented straightway by the orchestra:
First Theme | Piano Concert No. 23, first movement
The bridge theme between the first and second themes of the exposition:
Bridge Theme | Piano Concert No. 23, first movement
Second Theme | Piano Concert No. 23, first movement
A development theme is introduced at the beginning of the development section:
Development Theme | Piano Concert No. 23, first movement
Cadenza
Composers were often the soloist in their own concertos, and improvised a flashy solo in the second half of the movement called a cadenza. In the case of Mozart's Piano Concerto No. 23, he took the extra step of writing out the cadenza, although he was an incredible improviser. The cadenza begins at 09:36.
Piano Concerto No. 23 in A Major: 1. Allegro | Wolfgang Amadeus Mozart, 1756–91 | If you'd like to hear the entire concerto, the second movement, Andante, is at 11:15. The third movement, Allegro assai, is found at 18:30.
Piano Concerto No. 23
