Maybe a bardic "lich" (untied from alignment restrictions) would need to continue performing old works for new people, or keep making new works, in order to stay "alive". So you either get someone who wanders the world, performing for new audiences and eventually returning to old places after a generation or two, or you get someone who can stay in one place so long as they constantly churn out new examples of their craft. With either path, you get a pretty different flavor to the classic lich huddled in a tower or castle away from the world except when they need to "eat"...