Srimad-Bhagavatam: Canto 7 - Chapter 1 - Verse 72


अहं च गायंस्तद्विद्वान् स्त्रीभि: परिवृतो गत: ।ज्ञात्वा विश्वसृजस्तन्मे हेलनं शेपुरोजसा ।याहि त्वं शूद्रतामाशु नष्टश्री: कृतहेलन: ॥ ७२ ॥


ahaṁ ca gāyaṁs tad-vidvānstrībhiḥ parivṛto gataḥjñātvā viśva-sṛjas tan mehelanaṁ śepur ojasāyāhi tvaṁ śūdratām āśunaṣṭa-śrīḥ kṛta-helanaḥ


Nārada Muni continued: Being invited to that festival, I also joined, and, surrounded by women, I began musically singing the glories of the demigods. Because of this, the prajāpatis, the great demigods in charge of the affairs of the universe, forcefully cursed me with these words: “Because you have committed an offense, may you immediately become a śūdra, devoid of beauty.”


As far as kīrtana is concerned, the śāstras say, śravaṇaṁ kīrtanaṁ viṣṇoḥ: one should chant the glories of the Supreme Lord and the holy name of the Supreme Lord. This is clearly stated. Śravaṇaṁ kīrtanaṁ viṣṇoḥ: one should chant about and glorify Lord Viṣṇu, not any demigod. Unfortunately, there are foolish persons who invent some process of kīrtana on the basis of a demigod’s name. This is an offense. Kīrtana means glorifying the Supreme Lord, not any demigod. Sometimes people invent Kālī-kīrtana or Śiva-kīrtana, and even big sannyāsīs in the Māyāvāda school say that one may chant any name and still get the same result. But here we find that millions and millions of years ago, when Nārada Muni was a Gandharva, he neglected the order to glorify the Lord, and being mad in the association of women, he began to chant otherwise. Thus he was cursed to become a śūdra. His first offense was that he went to join the saṅkīrtana party in the company of lusty women, and another offense was that he considered ordinary songs, like cinema songs and other such songs, to be equal to saṅkīrtana. For this offense he was punished with becoming a śūdra.