This study examined the molecular underpinnings of group instrumental music improvisation as well as verbal improvisation in musicians and nonmusicians using blood-based measurements of oxytocin, vasopressin, dopamine, and cortisol, with verbal improvisation serving as a control. All participants (N = 8) were able to successfully complete study tasks as directed and tolerate the blood draws. On average, regardless of musicianship status, males had a greater and directionally divergent change in cortisol when compared to females (males M = -.033; females M = .025) after improvising musically (p < .04). Males also had a significant difference between the decrease in cortisol after music improvisation (M = -.033) compared to an increase in cortisol after verbal improvisation (M = .026; p < .01). The current investigation provided promising results regarding the ability of the study design and procedures to yield useful information when bringing the study to scale with a sufficiently powered sample indicating potential sex and modality based differences.