I think the song might be about communication through various mediums, like art. "through what does it run/ and who is hearing" would be referencing those who are listening and paying attention to your work whom you don't even know. Imagining "all the terrain" would be realizing how different these people are, the different experiences which make them different from you. "Do you keep holding on?" -Do you continue to express yourself even though you don't know if anyone is listening?
I think the song might be about communication through various mediums, like art. "through what does it run/ and who is hearing" would be referencing those who are listening and paying attention to your work whom you don't even know. Imagining "all the terrain" would be realizing how different these people are, the different experiences which make them different from you. "Do you keep holding on?" -Do you continue to express yourself even though you don't know if anyone is listening?