Comparison of the absorption maxima with the hydrogen bonding of the C-2 acetyl groups for various mutants and wild-type bacterial antenna complexes has demonstrated a role for this molecular interaction in the tuning of the absorption properties of these complexes. There is a consistent linear relationship, between the downshift in the bacteriochlorophyll a C-2 acetyl stretching mode and the red shift in the absorption maximum, in both core and peripheral antenna complexes. This Linear relationship allows us to estimate the contribution of H-bonding to the red shifts of these complexes and the sensitivity of the absorption to changes in the C-2 acetyl group environment. Investigation of changes in the Raman spectra caused by altering the excitation conditions reveal either no or only minor changes in the positions of the methine bridge, the C-2 acetyl, and the C-9 keto stretching modes. We interpret the lack of sensitivity of these bands to the resonance condition as indicating that neither differences in ring distortion nor in the H-bonding environment of these groups are important in determining the heterogeneous absorption bandwidth of the absorption spectrum of these complexes. We suggest that the differences in coupling between the pigments might be responsible for the static disorder and this may also be partially reflected in the small differences in the C-9 keto group stretching band we observe in the Raman spectra.