What instrument did Leonardo da Vinci design to make a continuous musical sound with many tuned pipes?

Leonardo da Vinci designed a mechanical organ to make continuous musical sound with many tuned pipes.

His organ designs used mechanical systems to supply air and control groups of pipes. One notable concept involved a rotating cylinder or barrel that could operate the instrument automatically, while another combined many pipes with a mechanism for producing sustained sound. These ideas connected music with the clockwork engineering Leonardo studied throughout his career.

The designs were not necessarily finished instruments, and surviving drawings do not prove that every proposed version was built. A mechanical organ differs from a hand-played pipe organ because a programmed or powered mechanism can control the sequence of notes. Leonardo also designed the viola organista, a separate keyboard-and-bowed-string concept.