At the urging of one of Handel's librettists, Charles Jennens, Milton's two poems, "L'Allegro" and "il Penseroso", were arranged by James Harris,[2][3] interleaving them to create dramatic tension between the personified characters of Milton's poems (L'Allegro or the "Joyful man" and il Penseroso or the "Contemplative man").

The popular concluding aria and chorus, "As Steals the Morn" is adapted from Shakespeare's The Tempest, V.i.65–68.

Michael O'Connell and John Powell have published an analysis of Handel's setting of the text in his musical treatment.

For instance, the "da capo" version of the aria "Straight mine eye hath caught new pleasures" is sung by a soprano (Gardiner, English Baroque Soloists, Monteverdi Choir, 1980) but the truncated recitative version is sung by a bass (Nelson, Ensemble Orchestra de Paris, 2000).

In 1988, Mark Morris choreographed a dance performance to accompany the music and poetry.