Prabhupada was critical of professional kirtaniyas in West Bengal. But many of them also and bad habits. Kirtana is not defined as a form of entertainment.
The idea that the concluding words of the Bhagavata’s opening stanza, “satyam param dhimahi,” speak of Krsna sankitanam because the word “dhimahi” is plural, is insightful. Meditation is usually a solitary affair. Further support for this contention can be drawn from SB 11.5.33’s description of Mahaprabhu, which states dhyeyam sada … te caranaravrindam, “Your lotus feet are the object of constant meditation.”
What kind of meditation can be constant, or performed anywhere at all times? Sri Krsna sankirtanam is niyamita smarane na kala, “It can be performed anywhere at any time with no hard and fast rules.” When he says this in his Siksastakam, Mahaprabhu is speaking about kirtanam but then includes nama smaranam (smarane). Practically he is merging the two together—kirtanam and smaranam. The illustrious Bhaktisiddhanta Saraswati Thakura Prabhupada has done the same when he writes kirtana prabhave smarana svabhave, “Engaging in kirtanam enables one to meditate on one’s true nature (svarupa).” This is also the verdict of revealed scripture. Brhad-bhagavatamrta states
vag-indriyam syad yadi samyatam sada
cittam sthiram sad-bhagavat-smrtau tada
samyak pravateta tatah smrtih phalam
“If the sense of speech, which sets all the external and internal senses in motion, is brought under control, then the mind becomes stable and can properly engage in transcendental remembrance of the Lord. Remembrance thus develops as the fruit of chanting.”
Real smaranam is the fruit of kirtanam. Furthermore,
sankirtanad dhyana-sukham vivardhate
dhyanac ca sankirtana-madhuri-sukam
‘smabhis tayos tad dvayam ekam eva tat
“Sankirtana expands the joy of meditation, meditation the sweet joy of sankirtana. In our experience the two methods fortify one another and are therefore actually one.”
Spoken by the inhabitants of Vaikuntha.