In music, ornaments are notes which are added to the main notes of a piece of music in order to make it more interesting. There are several types of ornaments, including trills and slides. Music of the Renaissance and Baroque periods have lots of ornaments. The composer usually shows what ornaments are needed by little signs written above the notes. In some pieces, especially in slow movements, the composers often did not show the ornaments that are needed: they expected the performers to put them in themselves. Understanding the correct way of ornamenting music used to be a very important part of the art of singing or playing a musical instrument.
The correct way of ornamenting music varied a lot from one country to another and from one century to another. Ideas about how music should be performed kept changing. It is important for musicians today, who want to play music from these older periods, to know as much as possible about historical musical styles. Sometimes we have to make guesses about what a composer might have wanted. Fortunately several composers and music theorists wrote books about how to play ornaments. This enables us to understand the different performing styles. Sometimes composers wrote a preface (introduction) in their music to explain to the performer how to play the ornaments they had written.
There are different kinds of ornaments. A “grace note” is a note written in smaller print, to show that its note value (how long it lasts) does not count as part of the total time value of the measure.
In Spain, these ornaments were called "diferenzias". They were used as early as the 16th century, when the first books with music for the guitar were produced. In French music they were called "agréments".
Ornaments were still written in music from the Classical music period although they are gradually used less and less as composers started to write precisely all the notes that were to be played. By the Romantic period they were hardly being used except for “tr” meaning “trill”.