There have been some changes in the official National Iranian Anthem as I understand, but it seems that Ey Iran is one of the most popular (from wiki:"Iranian opposition groups both inside and outside of Iran do not recognize the current official anthem of the Islamic Republic of Iran as the "national anthem" and in all gatherings and ceremonies use "Ey Irân" anthem"). The Sorud-e Melli is the current official anthem, and before that it was the Payandeh Bada Iran. So is it true that on less official occasions the Ey Iran is sung rather than the current official anthem? I really like the powerful declamation of Ey Iran by the way :) Which one do you like the most?