▁Gu ests ▁ ▁As ▁in ▁G ers h win ' s ▁later ▁opera ▁P org y ▁and ▁B ess , ▁all ▁the ▁singing ▁roles ▁are ▁African - American ▁characters . ▁Un like ▁P org y ▁and ▁B ess , ▁however , ▁the ▁original ▁production ▁of ▁Blue ▁Monday ▁was ▁performed ▁by ▁white ▁sing ers ▁in ▁black face . ▁ ▁Setting : ▁A ▁bas ement ▁c afé ▁near ▁the ▁intersection ▁of ▁ 1 3 5 th ▁Street ▁and ▁Len ox ▁Avenue ▁in ▁Har lem , ▁New ▁York ▁City . ▁Time : ▁An ▁evening ▁during ▁the ▁Jazz ▁Age , ▁beginning ▁at ▁around ▁ 9 : 3 0 ▁P . M . ▁ ▁After ▁a ▁brief ▁over t ure , ▁the ▁g amb ler ▁Joe ▁appears ▁in ▁front ▁of ▁the ▁cur tain ▁as ▁a ▁Pro log ue , ▁in ▁a ▁reference ▁to ▁the ▁character ▁T onio ' s ▁opening ▁aria ▁in ▁P aglia c ci . ▁Like ▁that ▁number , ▁which ▁explained ▁the ▁serious ▁nature ▁of ▁Leon c aval lo ' s ▁opera ▁as ▁if ▁it ▁were ▁an ▁actual ▁event , ▁Joe ▁tells ▁his ▁audience ▁that ▁just ▁like ▁" the ▁white ▁man ' s ▁opera ", ▁this ▁" color ed ▁[ Har lem ] ▁tra ged y ▁en act ed ▁in ▁oper atic ▁style " ▁focus es ▁on ▁prim al ▁human ▁emot ions ▁such ▁as ▁love , ▁hate , ▁passion ▁and ▁je alous y , ▁and ▁that ▁the ▁moral ▁of ▁the ▁story ▁is ▁that ▁trag ic ▁results ▁come ▁from ▁when ▁a ▁woman ' s ▁intu ition ▁goes