God has much to say about singing in his word and he has given us many songs within his word. The book of Psalms contains 150 songs. He has given us the Song of Solomon and other songs within other books. God tells us that it is good to praise God with singing:
Praise ye the LORD: for it is good to sing praises unto our God; for it is pleasant; and praise is comely.
I will sing of the mercies of the LORD for ever: with my mouth will I make known thy faithfulness to all generations.
Singing is not new. There was singing when God created this universe:
Where wast thou when I laid the foundations of the earth? declare, if thou hast understanding. Who hath laid the measures thereof, if thou knowest? or who hath stretched the line upon it? Whereupon are the foundations thereof fastened? or who laid the corner stone thereof; When the morning stars sang together, and all the sons of God shouted for joy?
There are songs of deliverance:
Thou art my hiding place; thou shalt preserve me from trouble; thou shalt compass me about with songs of deliverance. Selah.
Therefore the redeemed of the LORD shall return, and come with singing unto Zion; and everlasting joy shall be upon their head: they shall obtain gladness and joy; and sorrow and mourning shall flee away.
Jesus sung with his disciples:
And when they had sung an hymn, they went out into the mount of Olives.
We can sing in our heart:
Speaking to yourselves in psalms and hymns and spiritual songs, singing and making melody in your heart to the Lord.
We can sing to others:
Let the word of Christ dwell in you richly in all wisdom; teaching and admonishing one another in psalms and hymns and spiritual songs, singing with grace in your hearts to the Lord.
We can sing anywhere and under any circumstances:
And when they had laid many stripes upon them, they cast them into prison, charging the jailor to keep them safely: Who, having received such a charge, thrust them into the inner prison, and made their feet fast in the stocks. And at midnight Paul and Silas prayed, and sang praises unto God: and the prisoners heard them.
Behold, God is my salvation; I will trust, and not be afraid:
for the LORD JEHOVAH is my strength and my song;
he also is become my salvation.
Praise the LORD; for the LORD is good:
sing praises unto his name; for it is pleasant.
I will sing unto the LORD as long as I live:
I will sing praise to my God while I have my being.
Sing praises to God, sing praises: sing praises unto our King, sing praises.