Diatonic in the context of "Ionian mode"

A chime (/ˈtʃaɪm/) or chime of bells is a carillon-like instrument, i.e. a pitched percussion instrument consisting of 22 or fewer bells. A Chime is primarily played with a keyboard, but can also be played with an Ellacombe apparatus. A Chime is often automated, in the past with mechanical drums connected to clocks and in the present with electronic action. Bellfounders often did not attempt to tune chime bells to the same precision as carillon bells. A chime of bells is defined as specifically having fewer than 23 bells to distinguish them from the carillon. American chimes usually have one to one and a half diatonic octaves. According to a recent count, there are over 1,300 existing chimes throughout the world. Almost all are in the Netherlands and the United States, with most of the remainder in Western European countries.