premise: Performers sing together on stage
hypothesis: They are singing a capella.
explanation_1: The second sentence states specifically that the style the singers are performing is a capella.
explanation_2: They can sing any sony not particulary capella
explanation_3: Just because performers sing together on stage does not mean they are singing a capella.
premise_logic: exists e1 s1 x1 x2.(on(e1,x2) & n_stage(x2) & a_together(s1) & Manner(e1,s1) & Actor(e1,x1) & v_sing(e1) & n_performer(x1))
hypothesis_logic: exists e1 x1 x2.(n_thing(x1) & Theme(e1,x2) & Actor(e1,x1) & v_sing(e1) & n_capellum(x2))