Young temperament

"Young temperament" may refer to either of a pair of circulating temperaments described by Thomas Young in a letter dated July 9, 1799, to the Royal Society of London. The letter was read at the Society's meeting of January 16, 1800, and included in its Philosophical Transactions for that year. The temperaments are referred to individually as "Young's first temperament" and "Young's second temperament", more briefly as "Young's No. 1" and "Young's No. 2", or with some other variations of these expressions.

Young argued that there were good reasons for choosing a temperament to make "the harmony most perfect in those keys which are the most frequently used", and presented his first temperament as a way of achieving this. He gave his second temperament as a method of "very simply" producing "nearly the same effect".