Haven't had a chance to test it, but the code looks good. Have you tested this out yet with nested tuplets? Cheers, MS http://codereview.appspot.com/5623051/diff/1/lily/beaming-pattern.cc File lily/beaming-pattern.cc (right): http://codereview.appspot.com/5623051/diff/1/lily/beaming-pattern.cc#newcode281 lily/beaming-pattern.cc:281: infos_[i].rhythmic_importance_ = -1; Could you include a comment indicating what the numbers mean in rhythmic importance?