A count of measures plus a beat location, i.e.
, (\+|-)?[0-9]+m\+[0-9]+(\.?[0-9]*)?. The
measure count is the number of bar lines crossed by the event, while the beat location
timestamp expressed as a beat with an optional fractional part. The measure number
must be in
the range of preceding measures to the number of remaining measures. A value with
measure number, such as "1m+3", indicates a point in the following measure, while
a value with
a negative measure number, such as "-1m+3", marks a point in the preceding measure.
number must be in the range from 0 to the numerator of the time signature plus 1.
in 6/8 the beat number must be within the range from 0 (the left bar line) to 7 (the
bar line). A value with a measure number of "0", such as "0m+2", indicates a point