An ostinato is a musical phrase that is repeated throughout a piece of music or a section of a song. Modern musicians don’t ordinarily use the term ostinato, and are more likely refer to a repeating section as a riff or pattern. Many different genres of music use ostinatos, but it is most noticeable in classical pieces such as Carmina Burana by Carl Orff and the early looping work of minimalists like Terry Riley. Repeating melodies, bass-lines, or percussive rhythm parts can all be classed as types of ostinato, and they are also useful techniques when it comes to writing music.
Most music could be classified as having some kind of repeating section within them. A lot of modern music is built in some way on repeating patterns, which are used for familiarity and a clear sense of rhythm. Most drumming patterns, for example, are made up of repetitive elements, accented occasionally with additional strikes, and the larger patterns themselves also often repeat throughout a song. A continuous repetition of any section of music can be referred to as an ostinato.
All different instruments are capable of producing an ostinato, whether it is a percussive one or a melodic one. For example, many piano players who play in “boogie woogie” style play a repeating bass-line with the left hand and play melody over the top of it with their right hand. This repeating left hand bass-line can be referred to as an ostinato. Many guitarists and bassists use repeating “riffs” in rock or pop songs, and they often continue for the entire introduction and verse. Even when a repeating section is varied slightly each time, if the core of the phrase is the same, it is still ostinato playing.
Looping is a musical movement heavily reliant on repetition. Musicians originally used tape decks to record small phrases of music and set them to play back on a constant loop. Whatever the original phrase was becomes an ostinato, and the musician then plays over that piece as if it were a backing track. This is done nowadays through digital devices called looper pedals, which can be thought of as ostinato machines.
Writing new compositions with the use of ostinato can make the process easier. After the basic, repeating skeleton of the beat is decided, the musician can then accent it and add to it, rather than working on an entirely different section to follow it. Just like a piano player improvising with his or her right hand over the repeating bass part held by the left, the musician uses the repeating phrase to hold the song together.