Only those persons who develop competency under the watchful eye of Sri Gurudeva does he authorize for dancing, singing, performing sankirtan, etc., in the association of similar-minded and affectionate devotees of Lord Hari, who are attached to bhajana. Following in the footsteps of Sri Gurudeva, they engage themselves in the mission of delivering the world, considering it their prescribed service. Incompetent people should perform japa of krsna-nama in solitude. In that kind of worship, one does not associate with others. Only a competent person will not be adversely affected by association with the public; rather, the outside community will be able to obtain the mercy of the Holy Name.
(from Srila Prabhupada’s Anubhasya commentary to Caitanya-caritamrta, presented in this book.)