There are many different musical forms. Here's a quick overview of some of the most common ones.
A concerto is usually composed for one or more soloists combined with an orchestra. It will usually be identified by three distinctly different movements. It evolved along with another music form the concerto grosso which was composed for a small instrumental group to play with an orchestrated backing. The concerto grosso wasn't used after the Baroque period, but the solo-based concerto continues to be played. The three instruments traditionally used in a concerto composition are piano, violin and cello but woodwind and brass solos are also known.
A symphony is best identified by its complexity. It isn't a form of music in its own right, but rather a style in which a composition is orchestrated. Usually it comprises four movements, the first of which being a sonata, however in the 18th century symphony was used as an interchangeable form for sinfonia and overture.
The word symphony comes from the Greek word meaning "agreement of sound" which is why despite the complex orchestration heard within the symphony, the integrity of harmony is kept intact. Haydn, Mozart and Beethoven were among the more famous symphony classical composers, but symphonies continue to be composed today. Although for the most part they remain to be composed for orchestras, there are some symphonies which are composed for specific instrument groups such as wind instrument bands.
This musical composition will comprise either three or four contrasting movement. Alongside the fugue it was one two musical foundations for concert music analysis. Most popular during the Classical period, the sonata was also composed during the earlier Baroque period, and later Romantic period.
Sonatas composed primarily as piano solos were the most common during the Classical period, although sonatas for violin and piano, or violin and cello were also composed. During the sonata's important classical period, the movements generally followed a generic three-movement layout of allegro, middle movement (slower such as an adagio or largo), a closing movement such as a dance minuet or another allegro.
In a four-movement composition the first three movements were as for a three-movement sonata, with the addition of a final movement in a fast tempo such as a sonata-rondo form. Although used by many composers, Beethoven was particularly fond of the sonata form with 32 piano sonatas plus sonatas for other instrumental combinations.
Sonatina's are a lighter version of sonatas. They have less than the four movements required in a sonata, the movements are shorter, and the level of complexity is lower - making them popular with students of the piano. This doesn't mean that they are all easy to play however, so you need to watch the skill level required for each piece. Usually a sonatina is composed as a piano solo but some composers also created works for both piano and violin.
This is a dance musical form from 17th century France. It is usually composed in quick double time although some composers use triple time. Similar to a gavotte, the bourree differs by starting on the last beat of a measure creating a quarter measure anacrusis (the gavotte has a half-bar anacrusis). Used by such composers as Bach, Chopin and Handel, the Bourree still exists today being used by contemporary artists such as Jethro Tull, and Tenacious D.
This is a distinct musical form where themes are repeated in a contrapuntal style with the various harmonies being interwoven one with the other. Dating back as far as the Middle Ages this musical style was popular in works of a canonic nature. A fugue opens with a main theme which is then imitated by each "voice" in the arrangement. Once each voice has imitated the theme, then exposition is said to be complete.
Sometimes this is followed by another new passage, or alternatively by a passage previously heard in the work. The fugue will close back in the originating key/tonic to which a coda is added. J.S. Bach, Beethoven and Mozart all created fugue compositions.
Duane Shinn is the author of a free newsletter on piano chords & chord progressions available at "Piano Lessons"