Board Thread:Questions and Answers/@comment-6517967-20130216021123/@comment-5923841-20130225215037

The Hunting Horn does impact damage like the Hammer. It can also cast buffs. Each move produces a different colored note, and certain combinations of (2-4) notes will create different buffs. Not all horns will be able to produce every note, so they can't all produce every buff.

The buffs and how to produce them are always the same, so the most advanced horn can produce all the same buffs as the most basic, but the basic doesn't have as wide a range as the more advanced horns.

Their relative damage compared to Hammers has varied from game-to-game. Check out the article Democide linked for more info.