MPR 7 (Cadence)
Strongly prefer a metrical structure in which cadences
are metrically stable; that is, strongly avoid violations
of local preference rules within cadences.
MPR 8 (Suspension) *
Strongly prefer a metrical structure in which a suspen-
sion is on a stronger beat than ist resolution.
MPR 9 (TimeSpan Interaction)
Prefer a metrical analysis that minimizes conflict in
the time-span reduction.
MPR 10 (Binary Regularity)
Prefer metrical structures in which at each level every
other beat is strong.
Metrical Deletion
Given a well-formed metrical structure M in which
i. B1, B2, and B3 are adjacent beats of M at level Li,
and B2 is also a beat at level Li+1,
ii. T1 is the time-span from B1 to B2 and T2 is the
time-span from B2 to B3, and
iii. M is associated with an underlying grouping
structure G in such a way that both T1 and T2 are
related to a surface time-span T' by the grouping
transformation performed on G of
(a) left elision or
(b) overlap,
then a well-formed metrical structure M' can be
formed from M and associated with the surface
grouping structure by
(a) deleting B1 and all beats at all levels between B1
and B2 and associating B2 with the onset of T', or
(b) deleting B2 and all beats at all levels between B2
and B3 and associating B1 with the onset of T'.
Time-Span Segmentation Rule 1
Reduction Every group in a piece is a time-span in the time-span
segmentation of the piece.
Segmentation Rule 2
In underlying grouping structure,
a. each beat B of the smallest metrical level deter-
mines a time-span TB, extending from B up to but
not including the next bar of the smallest level,
b. each beat B of metrical level Li determines a
regular time-span TB, which is the union (or sum)
of the time-spans of all beats of level Li-l (the next
smaller level) from B up to but not including
(i) the next beat B' of level Li* or
(ii) a group boundary,
whichever comes sooner, and
c. if a group boundary G intervenes between B and
the preceding beat of the same level, B |