where does the cadenza usually occur in a concerto
Cadenza The term cadenza often refers to a portion of a concerto in which the orchestra stops playing, leaving the soloist to play alone in free time (without a strict, regular pulse) and can be written or improvised, depending on what the composer specifies. Sometimes, the cadenza will include small parts for other instruments besides the soloist; an example is in Sergei Rachmaninoff's Piano Concerto No. 3, where a solo flute, clarinet and horn are used over rippling arpeggios in the piano. The cadenza normally occurs near the end of the first movement, though it can be at any point in a concerto. An example is Tchaikovsky's First Piano Concerto, where in the first five minutes a cadenza is used. The cadenza is usually the most elaborate and virtuosic part that the solo instrument plays during the whole piece. At the end of the cadenza, the orchestra re-enters, and generally finishes off the movement on their own, or, less often, with the solo instrument.
Orchestra A full-size orchestra may sometimes be called a symphony orchestra or philharmonic orchestra. The actual number of musicians employed in a given performance may vary from seventy to over one hundred musicians, depending on the work being played and the size of the venue. The term chamber orchestra (and sometimes concert orchestra) usually refers to smaller-sized ensembles of about fifty musicians or fewer. Orchestras that specialize in the Baroque music of, for example, Johann Sebastian Bach and George Frideric Handel, or Classical repertoire, such as that of Haydn and Mozart, tend to be smaller than orchestras performing a Romantic music repertoire, such as the symphonies of Johannes Brahms. The typical orchestra grew in size throughout the 18th and 19th centuries, reaching a peak with the large orchestras (of as many as 120 players) called for in the works of Richard Wagner, and later, Gustav Mahler. In recent decades some orchestras have returned to the Baroque, Classical and Early Romantic seating of musicians; second violins to the right, cellos and violas to the center which gives the music a stereophonic effect.