['Listening to music as a means of inducing a sense of calm and relaxation has been known for some time. Although these effects are robust, little research has been conducted into exploring the underlying neurochemical changes, which must occur to provide an individual with these objective sensations.', 'In the current report we utilize an AB design to explore observed differences in blood plasma signaling molecules in pre- and post music listening groups when compared with controls. We focus chiefly on cytokines, as well as peripheral blood mononuclear cells and polymorphonuclear cells. We utilized reverse transcription followed by real-time polymerase chain reactions to determine relative mRNA expression for the mu opiate receptor gene. Using high pressure liquid chromatography coupled to electrochemical detection as well as nano electrospray ionization double quadrupole orthogonal acceleration time of flight-mass spectrometry we determined opiate alkaloid levels.', "Our findings are two-fold: with regard to mu opiate receptor expression, mononuclear cells showed a statistically significant increase in subjects in the music group compared to the control. Plasma morphine levels were found to be non-significantly lower in subjects after listening to music when compared to control subjects whereas morphine 6 glucuronide levels increased slightly, suggesting morphine's conversion to morphine 6 glucuronide. IL- 6 levels were significantly lower as well whereas IL-1b, IL-10 and cortisol values were unchanged."] Does music alter constitutively expressed opiate and cytokine processes in listeners?