In ancient times the horn was a musical instrument used both in music and celebration, as well as an instrument to call the people together.
Joshua 6:5 - And it shall come to pass, that when they make a long [blast] with the ram's horn, [and] when ye hear the sound of the trumpet, all the people shall shout with a great shout; and the wall of the city shall fall down flat, and the people shall ascend up every man straight before him.
Joshua 6:6 - And Joshua the son of Nun called the priests, and said unto them, Take up the ark of the covenant, and let seven priests bear seven trumpets of rams' horns before the ark of the LORD.
Psalms 148:14 - He also exalteth the horn of his people, the praise of all his saints; [even] of the children of Israel, a people near unto him. Praise ye the LORD.
Lamentations 2:17 - The LORD hath done [that] which he had devised; he hath fulfilled his word that he had commanded in the days of old: he hath thrown down, and hath not pitied: and he hath caused [thine] enemy to rejoice over thee, he hath set up the horn of thine adversaries.
Psalms 75:4 - I said unto the fools, Deal not foolishly: and to the wicked, Lift not up the horn:
Psalms 75:5 - Lift not up your horn on high: speak [not with] a stiff neck.
The Bible mentions the "horn" many times and in many contexts:
Micah 4:13 - Arise and thresh, O daughter of Zion: for I will make thine horn iron, and I will make thy hoofs brass: and thou shalt beat in pieces many people: and I will consecrate their gain unto the LORD, and their substance unto the Lord of the whole earth.
Exodus 21:29 - But if the ox were wont to push with his horn in time past, and it hath been testified to his owner, and he hath not kept him in, but that he hath killed a man or a woman; the ox shall be stoned, and his owner also shall be put to death.
1 Samuel 2:1 - And Hannah prayed, and said, My heart rejoiceth in the LORD, mine horn is exalted in the LORD: my mouth is enlarged over mine enemies; because I rejoice in thy salvation.
Zechariah 1:21 - Then said I, What come these to do? And he spake, saying, These [are] the horns which have scattered Judah, so that no man did lift up his head: but these are come to fray them, to cast out the horns of the Gentiles, which lifted up [their] horn over the land of Judah to scatter it.
1 Chronicles 25:5 - All these [were] the sons of Heman the king's seer in the words of God, to lift up the horn. And God gave to Heman fourteen sons and three daughters.
1 Samuel 16:1 - And the LORD said unto Samuel, How long wilt thou mourn for Saul, seeing I have rejected him from reigning over Israel? fill thine horn with oil, and go, I will send thee to Jesse the Bethlehemite: for I have provided me a king among his sons.
1 Samuel 2:10 - The adversaries of the LORD shall be broken to pieces; out of heaven shall he thunder upon them: the LORD shall judge the ends of the earth; and he shall give strength unto his king, and exalt the horn of his anointed.
Lamentations 2:3 - He hath cut off in [his] fierce anger all the horn of Israel: he hath drawn back his right hand from before the enemy, and he burned against Jacob like a flaming fire, [which] devoureth round about.
Daniel 7:11 - I beheld then because of the voice of the great words which the horn spake: I beheld [even] till the beast was slain, and his body destroyed, and given to the burning flame.
1 Samuel 16:13 - Then Samuel took the horn of oil, and anointed him in the midst of his brethren: and the Spirit of the LORD came upon David from that day forward. So Samuel rose up, and went to Ramah.
1 Kings 1:39 - And Zadok the priest took an horn of oil out of the tabernacle, and anointed Solomon. And they blew the trumpet; and all the people said, God save king Solomon.
Daniel 8:5 - And as I was considering, behold, an he goat came from the west on the face of the whole earth, and touched not the ground: and the goat [had] a notable horn between his eyes.
Daniel 8:8 - Therefore the he goat waxed very great: and when he was strong, the great horn was broken; and for it came up four notable ones toward the four winds of heaven.
Daniel 8:21 - And the rough goat [is] the king of Grecia: and the great horn that [is] between his eyes [is] the first king.
Psalms 112:9 - He hath dispersed, he hath given to the poor; his righteousness endureth for ever; his horn shall be exalted with honour.
2 Samuel 22:3 - The God of my rock; in him will I trust: [he is] my shield, and the horn of my salvation, my high tower, and my refuge, my saviour; thou savest me from violence.
Psalms 18:2 - The LORD [is] my rock, and my fortress, and my deliverer; my God, my strength, in whom I will trust; my buckler, and the horn of my salvation, [and] my high tower.
Daniel 7:20 - And of the ten horns that [were] in his head, and [of] the other which came up, and before whom three fell; even [of] that horn that had eyes, and a mouth that spake very great things, whose look [was] more stout than his fellows.
Ezekiel 29:21 - In that day will I cause the horn of the house of Israel to bud forth, and I will give thee the opening of the mouth in the midst of them; and they shall know that I [am] the LORD.
Daniel 8:9 - And out of one of them came forth a little horn, which waxed exceeding great, toward the south, and toward the east, and toward the pleasant [land].
Psalms 132:17 - There will I make the horn of David to bud: I have ordained a lamp for mine anointed.
Luke 1:69 - And hath raised up an horn of salvation for us in the house of his servant David;
Job 16:15 - I have sewed sackcloth upon my skin, and defiled my horn in the dust.
Psalms 89:17 - For thou [art] the glory of their strength: and in thy favour our horn shall be exalted.
Jeremiah 48:25 - The horn of Moab is cut off, and his arm is broken, saith the LORD.