Of course, what we software writers want to know, is What do you WANT composition software to be able to do?

Is it?

1. Just to write down/import the full score of a tune which you have already conceived and can play on an instrument. Nothing but a musical typewriter on which you can type notes, edit and play.

2. To assist in CREATING a composition

To implement guidelines for creating a melody in a particular style

For example, the structure of a jig is fairly standard, in terms or repeating phrases and of intervals used. A hornpipe is also well-structured, but tends to use different typical intervals.

To suggest suitable chords

To convert chord names into full chords, in appropriate forms and inversions for the selected instrument

3. To assess a composition for adherence to rules, perhaps of structure, melody or harmony?

An example could be to check that all the bars correspond to the stated time signature. (HARMONY does this)

To implement or check against the rules of harmony would need a rule-based engine. Also note that the traditional rules taught for years have recently been shown to be incorrect!

4. Orchestration : To establish whether the tune is playable on the selected instrument

5. To assist in converting a tune from one format to another.
An example is the facility in HARMONY to convert a melody into a round.

6. To provide 'brainstorming' features to try to enhance your own creativity. HARMONY can play tune backwards, and can also create totally new, randomly generated, tunes which are guided by the structure of a selected style, e.g. jig, reel, hornpipe. These can then be modified as needed.