The official festivities take place in Islamabad and commence with the raising of the national flag on the Parliament House and the Presidency followed by a 31-gun salute in the capital and a 21-gun salute in provincial capitals. The President and Prime Minister of Pakistan address the nation in live telecasts. Government officials, political leaders and celebrities deliver messages or speeches during rallies, ceremonies and events, highlighting Pakistani achievements, goals set for the future, and praise the sacrifices and efforts of national heroes. Government buildings including the Parliament House, Supreme Court, President House and Prime Minister's Secretariat are decorated and illuminated with lights and bright colours. A change of guard takes place at national monuments by the Armed Forces. The Army, Air Force and Navy feature prominently in independence day parades. In the cities around the country, the flag hoisting ceremony is carried out by the nazim (mayor) belonging to the respective constituency, and at various public and private departments the ceremony is conducted by a senior officer of that organisation. In 2017, the Pakistan International Airlines introduced a special in-flight jam session to entertain passengers traveling on Independence Day, featuring artists singing national songs on board a domestic flight.