  We analyze orbital solutions for 48 massive multiple-star systems in the
Cygnus OB2 Association, 23 of which are newly presented here, to find that the
observed distribution of orbital periods is approximately uniform in log P for
P<45 d, but it is not scale-free. Inflections in the cumulative distribution
near 6 d, 14, d, and 45 d, suggest key physical scales of ~0.2, ~0.4, and ~1
A.U. where yet-to-be-identified phenomena create distinct features. No single
power law provides a statistically compelling prescription, but if features are
ignored, a power law with exponent beta = -0.22 provides a crude approximation
over P=1.4 -- 2000 d, as does a piece-wise linear function with a break near 45
d. The cumulative period distribution flattens at P > 45 d, even after
correction for completeness, indicating either a lower binary fraction or a
shift toward low-mass companions. A high degree of similarity (91% likelihood)
between the Cyg OB2 period distribution and that of other surveys suggests that
the binary properties at P<25 d are determined by local physics of disk/clump
fragmentation and are relatively insensitive to environmental and evolutionary
factors. Fully 30% of the unbiased parent sample is a binary with period P < 45
d. Completeness corrections imply a binary fraction near 55% for P < 5000 d.
The observed distribution of mass ratios 0.2<q<1 is consistent with uniform,
while the observed distribution of eccentricities 0.1<e<0.6 is consistent with
uniform plus an excess of e ~ 0 systems. We identify six stars, all
supergiants, that exhibit aperiodic velocity variations of ~30 km/s attributed
to atmospheric fluctuations.
