> If you want alternate tracks (for subtitles and audio) to work consistently, use Matroska.

And avoid GStreamer-based players. Totem is absolutely horrible if the subtitles are complicated (i.e. karaoke timing or multi-language). VLC seems to get it right most of the time.

The one-package container deal to pack it all sounds very interesting and nice. Could you perhaps have the lyrics be in a Matroska audio container?

I think there's lots of potential for file browsers that can work off on metadata enclosed in containers. I really hope these catch on.