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. Colossians 3:16
"Psalms, Hymns and Spiritual Songs"
The next aspect of Colossians 3:16 is discussing the actual meaning of "psalms, hymns and spiritual songs." In defining "psalms, hymns and spiritual songs" there is confusion and "defending of territory." Below is a brief, and hopefully helpful, explanation of these three terms.
PSALM
Almost everyone is in agreement that the term "psalm" refers to the singing of psalms from the Old Testament book by the same name. The only confusion arises when we note that the word "hymn" used by the gospel writers, Matthew and Mark in referring to the singing of Jesus and His disciples in the "Upper Room", references the singing of Psalm 118. The "Psalms only" singing movement believes that "hymns and spiritual songs" refer to psalms rather than hymns and songs. One of their primary arguments is that the Septuagint (the Greek translation of the Old Testament written nearly 300 years before Christ) uses these identical Greek words to describe Old Testament psalms. Because of the prolific use of hymns in the early church, this view, however, is seriously weakened.
HYMN
As early as 112 AD, a secular source (Pliny the Younger) describes as "Christians met early in the morning...singing and to Christ as a god." For the first 200 years of the church, there are actually more references by the early church fathers to the singing of hymns than psalms. One of the earliest extant hymns, "O Gladsome Light" was written sometime around 200-250 AD. St. Ambrose's most famous hymn (hymn #56 in Trinity Hymnal) was written in the 4th century to strengthen the teaching that Jesus Christ was fully God and fully man. Many biblical scholars (See Ralph Martin, A Hymn of Christ) believe that various New Testament passages such as Colossians 1:12-16 or Philippians 2:5-11 were used as hymns in the early church.
SPIRITUAL SONG
Of the three terms in Colossians 3:16, this is the most confusing. Many have taught that it refers to "singing in the spirit" or singing in tongues. While the term is never again mentioned in Scripture, ecstatic singing is not the intent of Colossians 3 or Ephesians 5.
JS Bach, perhaps the greatest of all musicians said this: "The aim of all music is the glory of God." Regardless of what we sing, this is why we sing!