"Macrotonal" may mean "containing no steps the size of a semitone or smaller". If we use the 12edo semitone as a standard, that would mean all steps are larger than 100 cents. Any scale that fits that simple constraint could be called a macrotonal scale.
Some possible further constraints on a macrotonal scale:
- macrotonal edo - a scale built from equal divisions of the octave with fewer divisions than 12. This is a finite set of 11 scales.
- macrotonal edonoi - a scale built from equal divisions of a non-octave interval (each of which measures larger than 100 cents). This is an infinite set.
- macrotonal non-equal - another infinite set. The traditional pentatonic scale of 2L 3s (such as you might find on the black keys of the piano) is one easy example. Also: