The World's Ugliest Music

Turns out that this piece of TEDx video provided some extra trivia for me:
1) SONAR: if the sound reflects back to you at high frequency, the object is moving towards you, low frequency away.

2) Piano has 88 notes.

3) Beautiful music has repeated motifs.

The last point - I wonder if this is a recurring motif in itself in the universe, that the desirables are often conserved and reiterated. Then maybe not: rarities are considered gems.