"Singer", "Singers" is a symbol, a spiritual characteristic of people engaged in religious activity in the "Temple" of God, i.e. among the people of God, who are able to satisfy the emotional needs of people, who are able to influence their emotions and feelings with their skillful preaching of the Word of God, to appeal to their soul and conscience, and so turn them to the fulfillment of God's Commandments, to glorify with songs the gracious Will of God. 

Negative Meaning.

"Singer", "Singers" - this is a characteristic of people who only declare in words, show their faithfulness, devotion to the fulfillment and evangelization of the Will of God, who with their religious eloquence put a person's mind to sleep, calm his conscience, develop in him only a sensual faith, zeal for God only emotional, but not based on a true understanding of His Word.