Ok. Imagine for example that you have to describe this using music: A spaceship arriving on a new planet discovering a new civilization.
So for me you have two main choice:
1. Lyrics: You take a singed song, commonly called a ballad made of the singer, the drum and his acoustic guitar. The way he would describe this is with lyrics, for example singing this accompanied by his guitar: "and then the spaceship came across the galaxy, gling gling gling, and the planet welcomed him, gling gling gling, (chorus) "I'm new on this new planet, and I face new technology I don't know..."
Ok This was an spontaneous example I just erupted out for fun...
So here it's the lyrics that make the description.
2. Music: An instrumental composition that actually describe this scenery with instruments organization and simply good musical structure and inspiration, well-made enough for you to SEE the picture without lyrics.
So here it's the music that make the description.
THAT'S what I'm searching for in instrumental music. I think it really takes more musical imagination and hard work to do that than just writing down some lyrics accompanied with acoustic guitar.
For example that's why I like Mike Oldfield; he actually manage to describe landscape and stories with a 20 minutes instrumental (not to mention the amazing 60 minutes Amarok).
And that's why I like video game music: when good, it can describe a whole place/story just musically.
And some movie score manage that, but it's not always great; a rare thing.
And that why I recently discovered Ozric Tentacles that is a pure psychedelic instrumental band that fits perfectly in my tastes.
I hope all this makes sense and that it will start some discussion here because I think it's a great subject.
And if anyone have some suggestion about imaginative instrumentals...