Perplex City - We Love Puzzles

It looks to me like these are describing notes to play on a trumpet, the mouth piece on the left may indicate amount of pressure (or whatever it is that varies the note with the same valves), the valves are indicated including what looks like a thumb valve underneath.

So I think this may be a tune that you need to identify.

Anyone here play the trumpet?

morse code

I'm wondering if each of these things is a different type of trumpet. I need to do more research, but it looks like trumpets come in different sizes. Even if the same valve configuration is used between two types of trumpets, a different note will be produced. Maybe this means this whole thing does decode to music.

Of course I'm not sure how the different circle and flare shapes play into this...

I'm going to guess that this is not a cipher of some kind.

You will really kick yourself when you get this one. I think this card is supposed to hint at a very famous computer game, then after this you should guess it. Just think sci-fi, what do they always seek?

I'm working from the trumpet angle. In my research I've read that longer trumpets are lower pitch, blowing with the lips wider apart make a lower pitch than with the lips closer together, and that all three valves up is a higher note than the first one down. Each "alien" has a circle that varies (which could be the mouth), different lengths, and valve positions. I don't think the size of the flare a the end matters since it seems to go along with the length.

So, putting this all together we can figure out the pitch of each "alien" relative to the others. I don't think there is any way to figure out the exact note (like B flat, A, etc..), but that probably doesn't matter. It's the relativity between all of them that matters.

Unfortunately, I'm stuck at the pitch sequence. It doesn't really look like a normal musical piece. Since the real answer is a planet, and there are classical pieces named for planets, I was thinking that this was a musical representation of that. However, there doesn't appear to be any such piece.

Maybe this is somehow related to Gustav Holst's "planets" suite

The known answer isn't represented.

I suppose it could be a reference to what's missing, but that seems overly obscure to me.
The music reference seems difficult enough, and this is "only" a black...