Why Hymns AND Psalms...
Ephesians 5:19New International Version (NIV)
19 speaking to one another with psalms, hymns, and songs from the Spirit. Sing and make music from your heart to the Lord,
Colossians 3:16New International Version (NIV)
16 Let the message of Christ dwell among you richly as you teach and admonish one another with all wisdom through psalms, hymns, and songs from the Spirit, singing to God with gratitude in your hearts.