I was surprised to read your news item that the UNPs 63rd birthday was celebrated without playing the national anthem because a cassette was not available.
In Sri Lanka no one needs a cassette to sing the national anthem. We must be able to sing it with our without a recording.
I have participated in several Dutch ceremonies. Since they do not have a recording they sing it with one voice. Even where there is a recording they sing it loud. It all depends on how you love your country and whether you take pride in singing the anthem.