Yes, it is very good if you can chant 64 rounds; this is very nice if you can do it. But first of all we should not be disturbed by any circumstances. If you do become disturbed then this means you are still deficient in reaching the point. In Bhagavad-Gita it is said that when Krishna is within our view, at that time one is not disturbed even in the midst of gravest calamity. Anyway, even if we are disturbed, then the only resort is to chant and concentrate one's mind in Krishna. There is no other alternative. Chanting and dancing make one relieved of all material burdens.
Letter to Hamsaduta, 23 March, 1969