no, if you want to smoothly move from one theme to the next go for it, but it's not a rule for the game. You can also switch gears completely if you wish for a new theme. really the only rules that ever were and that remain are: * you get one choice per theme * no fantasy entries; your pick has to be one that has been officially released in some format (so, no unreleased live tunes, no demos that aren't available - basically no "bootleg" stuff and no made up stuff) * whoever finishes one theme gets to kick off the next apart from that, the themes can be as hard or as easy as you wish, so long as none of these basic rules are compromised. I'd like to think that this far into the game we don't need to renegotiate any of these principles. I think it would be a lot less fun if it were a total free-for-all, personally.