No other Kirtan is recommended
No other kirtana is recommended. This hari-kirtana was started five hundred years ago in Bengal by Lord Caitanya. In Bengal there is competition between the Vaisnavas and the saktas. The saktas have introduced a certain type of kirtana called kali-kirtana. But in the Vedic scriptures there is no recommendation of kali-kirtana. Kirtana means hari-kirtana. One cannot say, "Oh, you are Vaisnava. You can perform hari-kirtana. I shall perform siva-kirtana or devi-kirtana or ganesa-kirtana." No. The Vedic scriptures do not authorize any kirtana other than hari-kirtana. Kirtana means hari-kirtana, the glorification of Krsna.
So this process of hari-kirtana is very simple: Hare Krsna, Hare Krsna, Krsna Krsna, Hare Hare/ Hare Rama, Hare Rama, Rama Rama, Hare Hare. Actually there are only three words: Hare, Krsna, and Rama. But they are very nicely arranged for chanting so that everyone can take the mantra and chant Hare Krsna, Hare Krsna, Krsna Krsna, Hare Hare. Hare Rama, Hare Rama, Rama Rama, Hare Hare.
From – The Science of Self Realization
By His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada