In plain words
Saṅkīrtana makes us recognise the unity within the many
‘Samyak kīrtanaṃ iti saṅkīrtanaṃ.’ There is a great difference between kīrtana and saṅkīrtana. Kīrtana is purely personal. It is one's own striving for what one would gain for oneself. Saṅkīrtana is what brings well-being to the whole universe itself. It is called ‘bhajan in a group’. It was first begun by Guru Nānak, the Guru of the Sikhs. This saṅkīrtana is what makes us recognise the unity within the many. Bhajan in which all voices join and sing out as one voice, in unity, is called ‘saṅkīrtana’. This saṅkīrtana is of four kinds. First, guṇa saṅkīrtana. Second, līlā saṅkīrtana. Third, bhāva saṅkīrtana. Fourth, nāma saṅkīrtana. Guṇa saṅkīrtana is to describe only the auspicious qualities of God, to become one with them, and to make the effort needed to build those same good qualities into one's own life. This guṇa saṅkīrtana is what Tyāgarāja did.
Since You are beyond the reach of speech, to praise Your story, even for Brahmā and the gods, is it possible? O Kṛṣṇa! I have waited for Your grace; hear my cry and protect me, Lord. You brought back and gave the guru's son whom Death had carried off; You crushed the pride of Death; You freed Vasudeva and Devakī from prison; You protected Draupadī of the lovely eyes; well done, well done, You guarded the Pāṇḍavas; You ended Kucela's distress; You took away the crookedness of the misshapen Kubjā; You protected the sixteen thousand fair women. Since You are beyond the reach of speech….