The effects of dissonant and consonant music on cognitive performance were examined. Situational dissonance and consonance were also tested and determined as the state where one's opinion is contrasted or matched with the majority's opinion, respectively. Subjects performed several cognitive tasks while listening to a melody arranged dissonantly, consonantly or under silence. Prior to hearing the music, subjects were given "worldwide opinions" of the music they were about to hear: adequate information (e.g. positive evaluation of consonant music), inadequate information (e.g. positive evaluation of dissonant music) or neutral information. Results showed that dissonant situations (musical as well situational) improved cognitive abilities. This was found under different cognitive loads. A possible explanation involves recalibration of the dissonance-consonance continuum with arousal. It may be that dissonance brings arousal to optimal levels, thus sharpening concentration. Ways to expand the understanding of dissonance and its effects on performance and cognition are discussed. (Contains 3 figures and 2 tables.)