Chetham's School of Music (/ˈtʃiːtəmz/ or occasionally /ˈtʃɛtəmz/) familiarly known as "Chets", is a specialist independent co-educational music school in Manchester city centre in North West England. It was established in 1969, incorporating Chetham's Hospital School, founded as a charity school by Humphrey Chetham in 1653. After becoming a boys' grammar school in 1952, the school turned to music as its specialism, and became an independent school. There are approximately 300 pupils on roll, making it the largest music school in the United Kingdom. The oldest parts of the school date to the 1420s, when the building was constructed as a residence for priests of the church now Manchester Cathedral; these parts are listed buildings, along with other parts of the complex. The site houses Chetham's Library, the oldest free public reference library in the United Kingdom.