In late Greek and medieval theory, the word was used for consonance, as opposed to (), which was the word for "dissonance". In the Middle Ages and later, the Latin form "symphonia" was used to describe various instruments, especially those capable of producing more than one sound simultaneously. Isidore of Seville was the first to use the word symphonia as the name of a two-headed drum, and from c. 1155 to 1377 the French form "symphonie" was the name of the "organistrum" or hurdy-gurdy. In late medieval England, "symphony" was used in both of these senses, whereas by the 16th century it was equated with the dulcimer. In German, "Symphonie" was a generic term for spinets and virginals from the late 16th century to the 18th century.