We have investigated the photodissociation spectroscopy of the Mg+-acetaldehyde bimolecular complex over the spectral range 220-400 nm. We find evidence for four distinct absorption bands in the near ultraviolet that correlate with Mg+-based and acetaldehyde-based transitions. Our results suggest that the Mg+-centered. 3p pi (A")<--3s(A') and acetaldehyde-centered pi*(A")<--n(A') transitions are mixed, and result-in significant vibrational excitation in the complex leading to broad and unresolved absorption bands. In contrast, the predominantly Mg+-based excitation bands, assigned as 3p(A')<--3s(A') and 3p sigma (A')<--3s(A'), each show prominent vibrational progressions identified with intermolecular wagging modes of the complex. These intermolecular wag progressions are short and anharmonic indicating low barriers to isomerization. in the 3p sigma (A')<--3s(A') band several higher frequency vibrational modes are also active and have been assigned to the Mg-OCHCH3 intermolecular stretch, a CCO deformation mode, and the C-O stretch.