Please accept my greetings. I am in due receipt of your letter dated Feb. 1, 1975 and have noted the contents. I am glad that you enjoyed our chanting. You are welcome to come again and again if you like. You should understand though that we are not very much concerned with the principles of Hatha-yoga. We practice Bhakti-yoga strictly and since Bhakti includes all other results obtained from practicing other yogas as it is declared in the Bhagavad-gita to be the culmination of all yogas it becomes unnecessary for us to apply any other techniques besides simply chanting and hearing about the Supreme Personality of Godhead, Krishna who is called Yogesvara or the master of all yoga. Of course, it is certain that if one sits with straight spine it may be of some help in his ability to concentrate, but it cannot be considered as essential by any means. That thing which is really essential in Bhakti is to develop one's eternal dormant love for Krishna.

I hope this meets you in good health.