Can national anthem be sung under the roof?

Yes, National Anthems can be sung under a roof, such as in indoor venues like arenas, theaters, or stadiums. The setting does not typically impact the appropriateness of singing the anthem, as it is often performed in various environments. However, the context and cultural norms may influence how it is received. Ultimately, the key is to show respect and reverence while performing the anthem, regardless of the location.