I still haven't read anything here that refutes my initial statement. Great music isn't always beautiful. Nor is great art nor are great ideas.
Some of us may prefer our notions of great truth, ideas and art to follow certain expressions, expressions which are generally regarded as having a form of beauty.
Not all of us share that sentiment, tho'. I'd hardly imagine that the paintings of Francis Bacon are generally regarded are beautiful; likewise much of the music of Filter.
The Impressionists, Fauves and other movements that have become common currency in the beautiful art market have created something of a backlash, a demand for the less than beautiful and even the deliberately ugly.
Understanding this paradox is among the most vital of all undertakings for any artist.