Researching musical instruments in Middle-earth has brought up interesting references and comparisons. I haven't yet counted, but it seems to me that horns are among the most frequently mentioned instruments - not always in the context of musical performance, often used as signal instruments. I'd like to discuss the instruments, occasions, players, etc. Which races play the horn, which individuals? Of what materials are they made, if mentioned?
I'll start with the very beginning ('...a very good place to start...'
): two of the Valar have and play (a) horn(s). (The only other instruments mentioned in direct connection with the Valar are the trumpets of Manwë.) Ulmo's horns are made of white shell, specified as conches, and are named the Ulumúri. He is said to be the one Valar most deeply instructed in music, and even only one note played by him can awaken a sea longing and bring visions, as we are told in the story of Tuor. I would imagine that this kind of playing could be interpreted as performance of music - with various sizes of shells, it would be possible to play a melody.
The other Valar horn is called Valaróma, the horn of Oromë, the hunter. (His name even means "horn-blowing" in Quenya, according to Foster's
Guide.) His horn is spoken of as a signal instrument in connection with hunting and has the effect of chasing evil enemies away with its blowing. The sound is described as being like scarlet sunrise or lightning - not necessarily melodic, though nothing mre than that is said about the nature of its music.
Which uses of horns occur to you? The title of this thread gives a rather obvious hint, of course...