The oboe is a double-reed instrument, an important part of the woodwind section of the modern orchestra. The mechanism of its keys underwent considerable development in the 19th century. In earlier times it formed an important part of the outdoor military band, but the Western symphony orchestra normally uses a pair of instruments. The oboe d'amore is the alto of the oboe family, used in the baroque period, and the tenor is found in the cor anglais or, in the mid-18th century, in the oboe da caccia. The tone of the instrument, much affected by different methods of cutting the reeds, can impart a characteristic sound to a whole orchestra.