Psalm 57:7...My heart is fixed, O God, my heart is fixed: I will sing and give praise.
When you can say with David, "My heart is fixed, O God, my heart is fixed", then you can, like David, very naturally and easily say, "I will sing and give praise."
William Law, 1686-1761, wote, "It is the hear that tunes a voice to sing the praises of God."