Personally I think the Prologue as sung by Gobbi is a marvellous gift from heaven! Unforgettable and simply superb. In this wonderful solo he tells us that the drama, although performed by actors, is about real human beings who like everyone else have ordinary human feelings. This is opera solo music at its finest.
In Act 1, the travelling players arrive at a small village and are greeted enthusiastically by the crowds, then soon move off to the local tavern leaving Nedda alone at homebase. She daydreams of being freed from her life there, free as the birds in the sky, and sings a wonderfully inspired aria filled with joy. To me it is a special musical moment to be remembered. Present only is Tonio, the simpleminded member of the group, who has a crush on Nedda but of course she is married to Canio, the leader. Tonio forces his attentions on her, moved by the love that stirs in his heart, but she scorns him, strikes him with a whip, and he backs away humiliated, vowing vengeance. This sets the tone for much of what follows as one feels a tension in the air whenever he's around.
Silvio (Lino Puglisi) is Nedda's lover and he next appears after Tonio has left the scene. He'd like to take Nedda away with him, wanting her to leave the group, and questioning her again what her feelings are for her older husband, Canio. Surely if she doesn't love him she shouldn't stay. She hesitates then reluctantly agrees to meet Silvio after that night's performance, to run off together, and they finish the scene with exquisite singing of their love and future life together. Such beautiful music.
Canio (Franco Corelli) is the jealous husband and now arrives, but he returns only to find Nedda with Silvio so he frantically chases after him but Silvio manages to escape and not be recognized. Not knowing exactly who it is Canio roughly demands that Nedda reveal his name. She doesn't give in to him however. The day moves on and it's time to prepare for the evening's performance.
We find in Act 2 that the play onstage begins with a Serenade sung by Beppe, very nicely performed by Mario Carlin. He plays Harlequin who sings to his ladylove, Columbine (Nedda). Canio has to play the part of Pagliaccio who suddenly bursts upon the stage and Harlequin runs away. This role playing is too close to home for Canio who lapses into the real life drama that started off stage. Now he demands from Columbine (his wife Nedda) the name of her lover and there is no pretending anymore. Thereafter is the denouement to follow.
When the opera was first performed it was not highly regarded by the critics but the major tenors of the time enjoyed the Pagliacci role and that helped to keep it popular. In modern times the opinion has mellowed and it's considered a very good example of expressive artistry, a nice compliment given that it's rather a short opera compared to most others. One gets to appreciate this music more and more after some serious listening. Well recommended.