The concerto form is written for solo instrument and accompanying orchestra. Typically, it will feature the soloist prominently, showcasing their ability on their instrument through virtuosic writing and exploring the technical boundaries of the instrument. Nearly all orchestral instruments can play concertos now, but in the past it was only certain instruments such as the violin which seemed in favour. Other less ‘soloistic’ instruments were sidelined to orchestral accompaniment roles only.
Traditionally, the soloist will stand at the front of the stage so as to stand out from the orchestra. It is customary to play a concerto without using music from memory, however with 2 or more soloists, the music will more likely be used. A concerto can be written fro one soloist alone, or for several soloists, each normally taking it in turns to shine in their own virtuosic passages. On occasion, the soloist may choose to join in the orchestral ‘tutti’ part, although again, this is usually at the discretion of the soloist themselves.
A concerto will normally be performed in a concert hall or on a stage. The orchestra usually uses a conductor, but on occasion, depending on the genre and era of the music, the soloist may conduct the orchestra as well as play their solo line. Historically, composers usually wrote concertos for specific famous soloists who they wanted to premier their piece. Almost all the major composers spanning from the baroque to the modern day era have written concertos for various instruments and for specific performers, giving the concerto a very firm seat in traditional compositional form.
The origins of the concerto began in the Baroque era with the concerto grosso. It was normally written for several solo instruments, for example 2 violins and a flute, known collectively as the ‘concertino’. The orchestra (including at this time the harpsichord) was called the ripieno. During the Baroque era, composers began experimenting with the technical parameters of the more prominent orchestral instruments such as the violin, flute, oboe and trumpet. These instruments were the most technically advanced and the ones which often played the melody line in an orchestral piece. Composers began to write specifically for these instruments and the concerto grosso was formed. At this time there was generally no conductor, so the soloists or the harpsichord player would lead the performance. The solo parts were moderately difficult by today’s technical standards, since instruments were still in the early stages of advancement. Those written in particular by Vivaldi and J.S. Bach were more technically demanding than most and required the most skill from the soloist.
The baroque concerto grosso as a form was more inclusive of the solo instrument within the orchestral writing. Often, the soloist would play the ripieno orchestral part as well and solo passages would be fairly short. As the concerto was developed during the classical period, the solo line became more prominent and lengthier. Additionally, it became more fashionable to write a concerto for just one solo instrument, so the concerto grosso as a form was less frequently used. The orchestra during the classical period expanded to include bassoons more frequently, clarinets (which had just emerged as an instrument during the classical period), french horns and in the late classical period, trombones. The string section became larger and the harpsichord was removed entirely, in its place the conductor led the performance. At the same time, technically advances meant that instruments were being honed and improved all the time, allowing the soloist to play more complex and technically demanding passages. The advancement of the violin, the viola and the cello during this time allowed for highly virtuosic writing and performers became much more skilled. Similarly woodwind instruments such as the flute, clarinet, oboe and bassoon all showcased new technical advances which allowed composers to write much more difficult and demanding passages for their soloists. At this time, the soloist as a performer became a real feature in the music world, becoming known for their technical brilliance across Europe and travelling far and wide to perform.
During the late classical / early Romantic era, concertos were in their heyday. At this point, the piano had undergone major overhauls in development to what we now know as the pianoforte. Instruments in general were now far more capable of allowing the soloist total control of dynamics, rubato, difficult scalic passages and control in the extreme high and low pitches of the instrument. The orchestra expanded again to include much bigger string sections, bass clarinets and contra bassoons, euphoniums and a larger and more diverse percussion section. Because of this, concertos were far more dynamic and extreme in terms of pitch, dynamics and virtuosic writing, so as to allow the soloist to cut above the orchestral accompaniment. During this time spanning the late romantic/ early 20th century era, composers began writing for all instruments of the orchestra, including those instruments such as the viola and trombone which had previously only be assigned to orchestral accompaniment roles. Even as far back as Mozart, composers did occasionally write for more obscure instruments, but it was in the early 20th century that all instruments seemed to have a shining role in the concerto more frequently.
A concerto usually consists of three separate movements, all of which are performed together in order. The first movement is usually a fast movement and will sometimes have a slow introduction. It is often in sonata form, although it can sometimes be in rondo form or a combination of both forms. The second movement is almost always a slow movement, showcasing the more lyrical qualities of the solo instrument. It is sometimes written in rondo form or theme and variations form. The third movement is a fast upbeat movement, often in compound time akin to a dance-like style and pace.