Acis and Galatea (HWV 49) is a musical work by George Frideric Handel with an English text by John Gay. The work has been variously described as a serenata, a masque, a pastoral or pastoral opera, a "little opera" (in a letter by the composer while it was being written), an entertainment and by the New Grove Dictionary of Music as an oratorio. The work was originally devised as a one-act masque which premiered in 1718. He later adapted the piece into a three-act serenata for the Italian opera troupe in London in 1732, which incorporated a number of songs (still in Italian) from Aci, Galatea e Polifemo, his 1708 setting of the same story to different music. He later adapted the original English work into a two-act work in 1739.

Several writers, such as musicologist Stanley Sadie, consider it the greatest pastoral opera ever composed. As is typical of the genre, Acis and Galatea was written as a courtly entertainment about the simplicity of rural life and contains a significant amount of wit and self-parody. The secondary characters, Polyphemus and Damon, provide a significant amount of humor without diminishing the pathos of the tragedy of the primary characters, Acis and Galatea. The music of the first act is both elegant and sensual, while the final act takes on a more melancholy and plaintive tone. The opera was significantly influenced by the pastoral operas presented at the Theatre Royal, Drury Lane during the early 18th century. Reinhard Keiser and Henry Purcell also served as influences, but overall the conception and execution of the work is wholly individual to Handel.

Acis and Galatea was by far Handel's most popular dramatic work and is his only stage work never to have left the opera repertory. The opera has been adapted numerous times since its premiere, with a notable arrangement being made by Wolfgang Amadeus Mozart in 1788. Handel never gave the work in the form in which it is generally heard today, since it contains music which, while by Handel, was never added by him.

The story comes from Dryden’s translation of the thirteenth book of Ovid’s Metamorphoses, which appeared in London in 1717. In a libretto of 1730, Alexander Pope is named as the author of Handel’s text, but in one of 1739 John Gay is credited; the words of the aria ‘Would you gain the tender creature’ are certainly by John Hughes. As Handel would have known the three poets through Lord Burlington’s circle it would not be unreasonable to suggest that all three may have had a hand in the libretto: such a practice was not uncommon.

Handel made numerous revisions of the score, especially for later revivals, adding extra movements (in Italian!) and a chorus version of ‘Happy we’ (rather than the original duet). He also increased the scoring to include violas (which were absent from the Cannons orchestra) and even a carillon in 1739. Some versions included a third tenor part for the character named Coridon, giving him Damon’s aria ‘Would you gain the tender creature’: in most versions, however, this fifth voice appears only in the choruses, being suited to either a very high tenor or a countertenor. (The possibility of the former must be considered as the Chapel choir at Cannons did not employ countertenors, though the range is much more suited to a falsettist.)

Source: Wikipedia (https://en.wikipedia.org/wiki/Acis_and_Galatea_(Handel ))

Although originally composed for Chorus & Orchestra, I created this Interpretation of "The flocks shall leave the mountains" from "Acis and Galatea" (HWV 49 Mvt. 17) for Winds (Flute, Oboe, French Horn & Bassoon) and Strings (2 Violins, Viola & Cello).