The psychological variables that were particularly influenced by social distancing during the COVID‐19 pandemic—stress, loneliness, social participation, and well‐being—correspond closely to variables that can also be influenced by music. The present study is a pilot randomized controlled trial examining the effects of online group singing on psycho‐physiological variables during the pandemic. Over 4 weeks, an online singing group sang together once a week, for 1 h, under the guidance of a professional voice coach. In a first control group, participants also met for 60 min per week but only discussed and exchanged personal experiences about music. A second control condition consisted of a waiting list group. Across all variables studied (positive and negative affect, life satisfaction, stress, loneliness, social participation, self‐efficacy, and body perception), positive effects were revealed in the singing group and in the discussion group, but not in the waiting list group. The effects of the variables self‐efficacy, social participation, loneliness, and life satisfaction were markedly stronger in the singing group than in the discussion group. The results demonstrate the effectiveness of group singing on a number of psycho‐physiological variables, which can be used profitably in and outside of times of crisis, in both clinical and non‐clinical settings.