  (Abridged) There is a diverse chemical inventory in protostellar regions
leading to the classification of extreme types of systems. Warm carbon chain
chemistry sources, for one, are the warm and dense regions near a protostar
containing unsaturated carbon chain molecules. Since the presentation of this
definition in 2008, there is a growing field to detect and characterise these
sources. The details are lesser known in relation to hot cores and in high-mass
star-forming regions -- regions of great importance in galactic evolution. To
investigate the prevalence of carbon chain species and their environment in
high-mass star-forming regions, we have conducted targeted spectral surveys of
two sources in the direction of Cygnus X -- AFGL 2591 and IRAS 20126+4104 --
with the Green Bank Telescope and the IRAM 30m Telescope. We have constructed a
Local Thermodynamic Equilibrium (LTE) model using the observed molecular
spectra to determine the physical environment in which these molecules
originate. We map both the observed spatial distribution and the physical
parameters found from the LTE model. We also determine the formation routes of
these molecules in each source using the three-phase NAUTILUS chemical
evolution code. We detect several lines of propyne, CH$_3$CCH, and
cyclopropenylidene, $c$-C$_3$H$_2$ as tracers of carbon chain chemistry, as
well as several lines of formaldehyde, H$_2$CO, and methanol, CH$_3$OH, as a
precursor and a tracer of complex organic molecule chemistry, respectively. We
find excitation temperatures of 20-30 K for the carbon chains and 8-85 K for
the complex organics. The CH$_3$CCH abundances are reproduced by a warm-up
model, consistent with warm carbon chain chemistry, while the observed CH$_3$OH
abundances require a shock mechanism sputtering the molecules into the gas
phase.
