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.