This study examined differences in the spontaneous electroencephalographic (EEG) signal in terms of music training and gender. Coherence estimates obtained by spectral analysis provided an efficacious method to study these differences. In the first study, differences in the spontaneous EEG between subjects with and without music training were observed. Subjects with music training exhibited significantly higher coherence values both within and between cerebral hemispheres when compared with subjects without music training. The most striking differences were observed in the two lowest (delta and theta) and two highest (beta 1 and beta 2) bands, with differences in the temporoparietal regions of both hemispheres being most prominent. The findings are discussed in terms of specialized organization of brain activity that influences cortical connectivity. Using the same method, differences in spontaneous EEG were also found between male and female subjects. Females tended to have significantly higher interhemispheric coherence values when compared with males. Both findings are also supported by recently discovered anatomic differences.