I love this. Each time I watch it, I'm discovering more. What you see is not what you get. This is the actual "band that starts playing different tunes". Most orchestra members aren't even musicians, but probably randomly chosen people in the audience. You can tell by the way some hold their instrument. One of the violin bows has it's hair hanging loose and in upper left there's a man holding a mandolin as if it's a violin, playing it with an invisible bow.
The conductor is not a conductor. Apart from the fact that he conducts events that are not occur, and doesn't conduct things that are, a real one would have never allowed a clarinet lady to stand up to unintentionally mimick an obscure atonal piece of John Cage while two melodious oboes are sounding. But he is trying very hard with dramatic arm movements and a serious expression on his face. Watch 0:20, I believe he's making "no-no-no not yet" gestures for the orchestra to put down their instruments again.
And then that adorable trumpettist: "Yes, I know... this is my solo. I started well on time. Hey... Why is this fellow in front of me pointing towards me? Is he trying to distract my attention or ...? Oh yes, I see, I must stand up. Almost forgot, sorry"
And of course there's the fade out, but no, this is no plagiarism. Ola Håkansson was just influenced!