The electronic structure of wurtzite GaN, Al0.5Ga0.5N, and AlN has been studied using synchrotron radiation excited soft x-ray emission spectroscopy. In particular, the elementally resolved partial densities of states has been measured and found to agree well with calculations. The shift in energy of the valence band maximum as x varies from 0 to 1 in AlxGa1-xN was measured by recording N K-emission spectra, and found to be linear. Furthermore, N K-emission spectra revealed resonantlike hybridization of N 2p and Ga 3d states at 19 eV below the GaN valence band maximum. The spectral intensity of this feature is proportional to Ga content.