This post is about the two Thai anthems that you might have heard when you visiting Thailand. Read this and you will not be surprised when seeing Thai stand still in the public!
The first anthem is Thai National Anthem (or Pleng Chat in Thai). This anthem is played twice daily. The first time is at 8.00 and the second time is at 18.00. You would hear the anthem on all radio and TV channels, in schools, public parks, and other public places.
In school, students are expected to come before 8.00 to sing the anthem. Besides, there would be two students raising the Thai flag up to the flag pole in the morning, and moving them back in the evening.
Thai people who hear the National Anthem will stop doing everything and stand up still in order to show respect until the anthem is finished.
The second anthem is The Royal Anthems. This anthem is usually played before the movie in cinemas and live performances, and same as Thai National Anthem, everyone will stand up still to show respect until anthem is finished. I have heard that there was a case that a Thai was arrested because he/she did not stand while the anthem was playing in the cinemas in Bangkok.
Hope this information helps.