In this case, common practice offers no obvious standard. I would probably extrapolate
from the rules for 6/4. In 6/4, the whole measure rest is just a single whole rest
while a half measure is half-plus-quarter or dotted half. Extrapolating for 6/1 would
mean
measure rest: quad-whole rest
Dennis Collins writes:
What's the standard rest for a whole measure in 6/1 (2 groups of 3
whole notes)? And for a half measure (3 whole notes)? Centered or
not? This is early 17th century stuff (and I don't want to halve the
values, but I assume the question would be the same with 6/2).
Ross