This is the earliest song in the Tanakh, from Exodus 15. I have edited it down, but have left it in its original Hebrew. It's a charming song about how great it is to have a god who will smite your enemies utterly.
The song, Shirat HaYam, is in Hebrew. Here is the English translation of the lyrics (words selected from Exodus Ch 15, verse numbers included)
1 I will sing to the Lord for He has triumphed gloriously.
Horse and rider He has hurled into the sea
3 The Lord the warrior,
Lord is his name
4 Pharaoh's chariots and army
He has cast into the sea
6 Your right hand, o Lord, glorious in power.
Your right hand, o Lord, shatters the foe
8 At the blast of your nostrils the waters piled up.
The floods stood straight like a wall.
The deeps froze in the heart of the sea
16 Terror and dread descend upon them
Through the might of your arm they are as still as stone.
Till your people cross over, o Lord,
Till your people cross, whom you have ransomed
11 Who is like you Lord among the gods?
Who is like you, majestic in holiness,
Awesome in splendour, working wonders?
18 The Lord will reign forever.