The 16-hole harmonica is a type of chromatic harmonica that is 16 holes long. It is a 4-octave harmonica. Therefore, the entire chromatic scale is available on the 16 holes chromatic harmonica. It starts an octave lower than the 12-hole chromatic harmonica. It allows the player to play in any key desired from just one harmonica. The 16 holes means the harmonica is able to produce 64 sounds. Thus, it is able to play more advanced repertoire. It is top-quality and offers fast response in all octaves. There are various brands of the 16-hole harmonica such as the swan chromatic harmonica and many more.