A masterpiece in my opinion is a combination of all the mentioned above, but it also implies the sence. But without the proper structure it won't sound good.
As an example I'd like to quote a piece by Rudyard Kipling from If
(sorry if I've changesd something - I write if by memory)
If you can fill the unforgiving minute
With 60 seconds worth of distance run.
Yours is the Earth and everything that's in it
And what is more - You'll be a Man, my son.