This is the Royal Anthem, “Glorify His Prestige” apparently without any words changed. The translation of the official Royal Anthem IS HERE. The joke in this music video is that the Royal Anthem is used to honor an important longtime critic of the monarchy; Somsak Jeemterasukul, a former history professor at Thammasat University, now a refugee in France. He is celebrated at the ongoing mass protests (as of September 2020), for being a source of truthful and solid information about the Thai monarchy, and opening many eyes. I can think of two bombshell news stories that he broke, which turned out to be true: one about Vajiralongkorn’s harem and another about Vajiralongkorn’s secret prison at Tawee Watana Palace. Also check out the song “สมศักดิ์ เจียมธีรสกุล” “Somsak Jeamteerasakul,” by Rishadan Port and Erosagape, which is also translated at this site.