“…Some of the earliest theories about the power of group singing were proposed by sociologists ( Durkheim, 1912/1995 , p. 232; Collins, 2004 , p. 61). Recent empirical studies have revealed that participatory singing does in fact create and reinforce community bonds ( Li and Southcott, 2012 , p. 67–70; Tarr et al, 2014 ; Balsnes and Jansson, 2015 , p. 168; Pearce et al, 2016 , p. 12–15). At the core of this research is the hypothesis that synchronization of voluntary and involuntary biological processes – a process termed “entrainment” ( Hayward, 2014 , p. 10; Thaut et al, 2015 ) – can promote altruistic behavior ( Kokal et al, 2011 ; Cirelli et al, 2014 ), increase positive feelings felt by participants toward one another ( Launay et al, 2014 ), enhance feelings of social connection and inclusion ( Lumsden et al, 2014 ; Welch et al, 2014 ), improve cooperation ( Valdesolo et al, 2010 ; Reddish et al, 2013 ), and raise trust levels ( Launay et al, 2014 ).…”