Sing a song ambassadors

Today May 5th is the date we celebrate Liberation from the 5 years of Nazi occupation during WW II and since some years this festival in the Netherlands has young performers singing their songs on various podia throughout the country and they're named for this day as the 'Ambassadors of Liberty'. Timetables and distances make that they travel by military helicopter for the day in order to sing their song in time ~ found the heli at Malieveld Den Haag