Galileo Galilei to the biography by Vincenzo Viviani) that these began by watching the swings of the bronze chandelier in the cathedral of Pisa, using his pulse as a timer. Later experiments are described in his "Two New Sciences". Galileo claimed that a simple pendulum is isochronous, i.e. that its swings always take the same amount of time, independently of the amplitude. In fact, this is only approximately true, as was discovered by Christiaan Huygens. Galileo also found that the square of the period varies directly with the length of the pendulum. Galileo's son, Vincenzo, sketched a clock based on his father's
Vincenzo Galilei in opera is widely attributed to Galilei, since he was one of the inventors of monody, the musical style closest to recitative. Galilei composed two books of madrigals, as well as music for lute, and a considerable quantity of music for voice and lute; this latter category is considered to be his most important contribution as it anticipated in many ways the style of the early Baroque. Vincenzo Galilei was one of the pioneers in the systematic study of acoustics, mainly in his research (assisted by his son Galileo) in the mathematical formula of stretched strings. Galileo told his biographer