Antonín Dvořák’s Rusalka is among the most popular Czech operas in the repertoire — not that there is a great deal of competition. It premiered in 1901, and though it has apparently enjoyed considerable popularity among Czech speakers in the meantime, I believe that it is only in the last few decades that it has become widely known in wider opera circles.
The story is based on a Hans Christian Andersen tale about a mermaid who falls in love with a man and is granted the opportunity, in exchange for her voice, to leave the sea to gain his love — the same story that inspired the Disney film The Little Mermaid. The resemblances don’t go very deep, however: in Dvořák’s version, Rusalka is betrayed by the prince, kills him with a kiss, and ends the opera as a water demon.
The music of the opera is quite beautiful. There is a good deal of wet and watery music, and Dvořák seems to have given the harp a prominent place in his score, lending it an enchanting quality. The vocal writing is pleasant, if not extremely memorable — with one notable exception: in Act I, when she first falls in love with the man, Rusalka sings the Song to the Moon, which surely ranks as one of the loveliest arias by Dvořák or anyone else. It is a beauty.
It is sung in this video by Anna Netrebko; I have posted this video before, mostly to make fun of it. Nonetheless, beggars cannot be choosers: