It would be "Mottainai" if people missed a chance to experient a nice mood.
Every year on 5-May a big concert takes place ON a Canal in Amsterdam. Since it's the liberation day of the Netherlands, the queen came there to enjoy the performance ON the water.
The stage was situated on the sluice-gate dam of Amstel, in front of Carre that is the Dutch royal theather in Amsterdam. The queen was waiting there until the time, so the place around there were surrounded by many police and/or the armys.
Some of the audience viewed the concert from their boat on the canal, though, most of them enjoy it from the banks or over the famous drawbridge named "Magerebrug". (There is an antient tradition that a pair who kissed under the bridge will love forever.)
The audience on board has closed to the VIP sheets where queen was sitting, so all of the audience on board should have been observed by the army from somewhere. I don't remember the music so much because I was discussing with one of my friends about something, and was already drunk because I could not see the stage completely obstructed by the roof of VIP sheets.
However it was very interesting night anyway. The fireworks were fantastic, and I could make good discussion with the friends, though, the concert was the main purpose!