An ostinato is a short melodic phrase, rhythm, chord or series of chords that is repeated multiple times throughout a work or in a section of it. The word is related to the word obstinate because it is a musical idea that is being obstinate and will not go away. Ostinatos can be repeated in identical form or with variations, such as with a different pitch or different instruments. Ostinato patterns have been used in European music since the Middle Ages and are common in many genres of music including various types of popular music and non-Western music. A well-known example is Ravel's Boléro, in which the same melody is repeated continuously with different instruments.