I understand also, there was a Kirtana performance given by Sri Purna das. You have rightly remarked whether they are devotees. You are right. These people are professional singers. Krishna Kirtana is not for earning livelihood. Krishna Kirtana is not meant for entertaining the public for demonstration of arts. It is dynamic service to the Lord. We do not therefore mind so much about the artistic presentation of Krishna Kirtana but we want to see how much a devotee is satisfying the Supreme Will.
From Srila Prabhupada’s letter to Jadurani — Calcutta 12 December, 1967