I like the idea of music, especially something ambient or even that type of music which is created more or less randomly on the spot; anything I won't get sick of until after hundreds of hours into the game, and then I could just turn it off. I think it's ridiculous to say that music isn't important in video games (...do I really have to give any examples?). And, yeah, you could just play your own music, but I want to point something out: if there was no music in JADE, you could just play your own music, but it wouldn't change or link up to the situation your character was in at all. If there was music in JADE, and you didn't like it, all you would have to do would be to select an option to turn it off; you wouldn't even notice it while someone else who enjoys it could leave it on, and, hopefully at least, it would link up.
I want to clarify with a couple of points, however. First, roguelike games are known for their simplicity, and, while I want a complex and rewarding game, many people want simplicity even maybe to a fault. I also think the amount of resources and time involved in doing this is great (especially if done well), and it would be impossible to have everyone agree on the music... and people are adamant about their music (and maybe even more-so about the music they don't like). If there will be music I wouldn't want to see it cemented until a much later release. Rather have a solid game than have Biskup work to death on the bells and whistles.
I think it was ToME or something that had a system with a few songs that you could optionally download, set in a folder, and change at will. So there would be songs for town, dungeon, and forest (and, in this case, not much else), but you could set them to whatever you like as long as it was a .whatever file. I'm hoping that there will be something more complex than this in JADE (music not just based on the vague type of level you were in; maybe based on your health or who knows what other factors); at least eventually. I rather like Plausible's and Grey's take on it; it's so modular and ever-changing.
I kinda feel the same way with graphics (like tiles), but I think it is more damaging than music if done wrong. For instance, if I'm too used to playing with graphics I might not know the abbreviations people use, or I might mistake/misjudge a type of monster/item/whatever when I'm playing a game, while in ADOM all the types of monsters look the same and I can just 'l'ook at them to make sure they aren't a special type that will kill or wreck me (especially in certain cases). Not that I never misjudged a monster in ADOM, but I've noticed I've done it more in ToME with graphics enabled than without. There are also problems when testing with graphics (especially new objects/monsters), and the fact someone has to create every tile, but I think I've gone off-topic enough.