Singing is defined as “sustained speaking”.  In St. Paul’s first letter to the Corinthians, chapter 12, the author says the following: “If I speak in human and angelic tongues but do not have love, I am a resounding gong or a clashing cymbal.”
When we sing, it is most uplifting when we do so with expression as we take the music from the printed page and make it come alive.
A cantor LEADS the assembly.  They do not PERFORM for the assembly.   The organist INVITES the assembly to participate by taking care to lead and not DOMINATE the assembly. 
St. Francis once said, “Singing is praying twice.”  What a beautiful expression when we do this as a unified body. 
St. Paul’s letter continues that “Love is patient”.  Music has the tendency, when done well, to soothe the soul.  In so doing, we can pray and reflect more deeply.