What constitutes the musical merit of a composition?

[xvimbi]

Since there were complaints about the lack of activity on this forum, here is a new thread:

What constitutes the musical merit of a composition?

I'll get the ball rolling:

Some compositions were ground-breaking in that their composers found new ways, techniques, formulas that had not been used before. Those are merits. However, those are merits in a historical sense. They are nothing ground-breaking anymore. They deserve admiration for their role at that time, but that's it. In other words, their merits become recognizable only if one knows about the music preceding or following those compositions, i.e. they acquire merits relative to other compositions. By themselves, they may not have much merit.

Other compositions enjoy a high reputation, because they are so well-crafted that only a true master could have conceived them.

Other things to consider:
Does a piece that is not performed have merits?
Does a piece that is often performed have merits?
Is technical difficulty a merit?
In yet other words: is novelty a merit?
Is "merit" a positive or a negative attribute? Both?

[Daevren]

To me the number of musical units is important. Whats that? Well what is music. To me it is the organisation of sound in terms of harmony, melody and rhythm. So a musical unit is a way to organise sound, melody and ryhthm. The more kinds of musical units or musical organisations in a piece the better.

Of course this is still abstract and subjective. So I am still trying to come up with something more functional and objective.

This is strictly musical merit. A piece could also have historical merit, or cultural merit. I find those things alot less important.