Aside from the horn of Boromir and the horns of Rohan, and Helm's horn, what comes most strongly to my mind is not just the horn that was given to Merry by Eowyn (which also seemed to have that quality of summoning friends and striking fear into the hearts of the enemy), but the fact that there was the "horn call of Buckland."
Fear, fire, foes! Awake, awake, awake! Gives one the impression that the foes mentioned were skulking nasties that came about in the middle of the night.
When I composed my symphony inspired by
The Fellowship of the Ring, I wanted to open the section of the first movement that was to be Merry's theme with my version of the horn call of Buckland, and it took I don't know how many failed attempts before I finally came up with notes I found acceptable (unfortunately, at the time, I had a rather poor synthesized MIDI orchestra, which had an abysmal horn sound, and now, even though my sampled instrument orchestra is much better, I haven't had the time and energy to sit down, rescore, and rerecord that movement -- yet. I'll get to it.
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