Sheet music is written represenation of music. Seen here is a piece called Adeste Fideles.

Sheet music is musical notation written down on paper; it is the musical analog of a book.

Reading sheet music is the standard way to learn and perform a piece in some cultures and styles of music. In western classical music, it is very rare for a performer to learn a piece in any other way. With the exception of piano, where memorization is expected, classical musicians ordinarily have the sheet music at hand when performing. Even in jazz music, which is mostly improvised, there is a lot of sheet music describing arrangements, melodies, and chord changes.

Sheet music is less important in other forms of music, however. In popular music, although sheet music is produced, it is nowadays more usual for people to learn the piece by ear (that is, by imitation). This is also the case in most forms of western folk music. Musics of other cultures, both folk and classical, are often transmitted orally, though some have sheet music, and a few use hand signals or some other device as a learning mnemonic.

The skill of sight reading is the ability of a musician to perform an unfamiliar work of music upon viewing the sheet music for it the first time. Sight reading ability is expected of professional musicians and serious amateurs who play classical music and related forms, especially for church musicians.

Types of sheet music

Sheet music may come in several different forms. If a piece is written for just one instrument (for example, a piano), all the music will be written on just one piece of sheet music. If a piece is intended to be played by more than one person, each person will usually have their own piece of sheet music, called a part. If there are a large number of performers required for a piece, there may also be a score, which is a piece of sheet music which shows all or most of the instruments' music in one place. Scores come in various forms:

• A full score is a large book showing the music of all instruments. It is large enough for a conductor to use in rehearsals and performance.
• A miniature score is like a full score, but reduced in size. It is too small for practical use, but handy for studying a piece of music.
• A study score is a rather vague term, sometimes used as a synonym for miniature score, and sometimes used to mean a score somewhere between the size of a full and a miniature score.
• A piano score (or piano reduction) is an arrangement for piano of a piece for many instruments. It will often include indications of which instrument plays the various melodies and other notes.
• A vocal score is a piano score that has all the vocal parts, both choral and solo, on separate staves. It is used by singers and to rehearse vocalists separately from the instrumental ensemble.
• A short score is a reduction of a work for many instruments to just a few staves. Short scores are not usually published, but are often used by composers on their way to producing a finished piece. Often, a short score is completed before work on orchestration begins.

It should be noted that the word score can also refer to the incidental music written for something such as a play, television programme, or film (when it is called a film score).

Popular music and jazz songs are often recorded using a lead sheet, which indicates the melody and lyrics, but only provides a rudimentary description of the harmony. Usually, this is done by writing the names of chords above the melody.

History

A putto holds the score for Saint Cecilia in Domenichino's painting of 1617-18 (Louvre Museum)

Before the 15th century, music was written by hand and preserved in large bound volumes.

The first machine-printed music appeared around 1473, approximately 20 years after Gutenberg introduced the printing press. In 1501, Ottaviano Petrucci published Harmonice musices odhecaton, which contained 96 pieces of printed music. Pertucci's printing method produced clean, readable music, but it was a long, difficult process that required three separate passes through the printing press. Single impression printing first appeared in London around 1520. Pierre Attaingnant brought the technique into wide use in 1528.

In 1575, Queen Elizabeth granted a monopoly on printing music to Thomas Tallis and William Byrd. This expired in 1596, when the monopoly was given to Thomas Morley instead.

In the 19th century the music industry was dominated by sheet music publishers. In the United States, the group of publishers and composers dominating the industry was known as "Tin Pan Alley". In the early 20th century the phonograph and recorded music grew greatly in importance. This, joined by the growth in popularity of radio from the 1920s on, lessened the importance of the sheet music publishers. The record industry eventually replaced the sheet music publishers as the music industry's largest force.

In the late 20th and into the 21st century, significant interest developed in representing sheet music in a computer-readable format. Several systems have been developed to do this, including Finale, Sibelius, GNU LilyPond, and GUIDO.

The Mutopia project is an effort to create a library of public domain sheet music, in a way similar to Project Gutenberg's library of public domain books.