ABSTRACT
There is no suggestion that in metrical music durational phrases are formed by premetrical connections independently of their metrical context. The perception of meter and the perception of phrase grouping go hand-in-hand, with phrases being understood within the established meter and phraselengths influencing the next level of metre (if any). Thus a further refinement of the program is the input of metrical information, so that durational phrase groupings may be read within a metrical context, irrespective of how this has been derived. Working from the lowest level upwards, metrical levels and their branches are merged with the pre-metrical ones as follows: (1) if a metrical branch is already present as a pre-metrical one, the latter is retained; (2) if a pre-metrical branch is contradictory with a metrical one on the same level, it is superseded by the latter; (3) pre-metrical branches that are not vertically aligned above established branches on the next lower level, are bypassed. In fact, the entire pre-metrical analysis is stored separately from the metrically adjusted one, both to preserve superseded structures as subsidiary ones and so that the durational grouping analysis may be transferred to the new structure. This is done by identifying the highest-level (metrical) branches that subtend the grouping as a whole, and placing a phrase marker at that level.
