Triumph in the God of Israel, and over the enemies of Israel. It calls to praise God in music and dance. God has chosen his people and helped them to victory. This psalm forms a regular part of Jewish, Catholic, Lutheran, and Anglican liturgies (Christian Worship). It is marked by its martial tone and calls on the people to be ready to fight. It was probably penned upon the occasion of some victory which Israel was blessed and honored with. “Sing a new song unto the Lord”. Similar to Psalm 96 and Psalm 98 (Cantate Domino)”Cantate Domino” is a Latin phrase that means “Sing to the Lord”. The English translation of the full verse is “Sing to the Lord a new song; sing to the Lord, all the earth. Sing to the Lord, and bless his name: announce his salvation from day to day. Announce among the nations his glory, and his wonders to all peoples”

It reads in Psalm 149:1-9 NIV
Praise the Lord. Sing to the Lord a new song, his praise in the assembly of his faithful people. Let Israel rejoice in their Maker; let the people of Zion be glad in their King. Let them praise his name with dancing and make music to him with timbrel and harp. For the Lord takes delight in his people; he crowns the humble with victory. Let his faithful people rejoice in this honor and sing for joy on their beds. May the praise of God be in their mouths and a double-edged sword in their hands, to inflict vengeance on the nations and punishment on the peoples, to bind their kings with fetters, their nobles with shackles of iron, to carry out the sentence written against them, this is the glory of all his faithful people. Praise the Lord.