What is the proper etiquette if an arrangement of national anthem played during a concert without singing words?

For the audience:

- Stand up if you are able.

- Remove any headwear, unless worn for religious reasons.

- Place your right hand over your heart.

- If you are not a citizen of the country whose anthem is being played, you may place your hand over your heart as a gesture of respect.

For performers:

- Play the anthem with accuracy and solemnity.

- Stand up while playing.

- Remove any headwear, unless worn for religious reasons.