def-tonality defines the tonality description(s) for an instrumental part. Def-description consists of instrument name and value. If the value is quoted list, it is associated directly to the instrument name, otherwise the evaluated value is used.
With compile-instrument this function must be used in tandem with def-zone. If you use compile-song then you won't need this function, since the tonality definitions are set inside it. But if you want to generate instrument structures directly with your own functions, then this function makes it possible to define tonality descriptions for each instrument.
(def-tonality
effects (activate-tonality (c# min 1 1))
chords (activate-tonality (c# maj 1 1) (d& maj 1 3) (e min 1 5))
