The Quintetto Chigiano or Chigi Quintet was an Italian musical ensemble comprising a string quartet with pianoforte, founded in 1939 and active until 1966, when it was reformed as the Chigiano String Sextet. Led by Riccardo Brengola, it was first assembled by Count Guido Chigi-Saracini out of his Accademia Musicale Chigiana at Siena in Tuscany, Italy, but developed a worldwide acclaim.