There have been innumerable pieces of music written about water spirits – sirens, naiads, lorelei, undines, mermaids and melusinas. This Sunday night on “The Lost Chord,” we’ll sample just a couple of these for Rusalka Week.

In Slavic mythology, a rusalka is a spirit that dwells at the bottom of a river or lake. She lures unsuspecting men with her song, invariably resulting in a watery doom. Rusalki are never more dangerous than in early June, when the spirits roam free.

Rusalka Week plays a role in Rimsky-Korsakov’s opera, “May Night,” drawn from Gogol’s collection, “Evenings on a Farm Near Dikanka.” Alexander Dargomizhsky’s opera, “Rusalka,” is based on a dramatic poem by Pushkin. And the best known of the bunch, Dvorak’s “Rusalka,” was inspired by Czech fairy tales of Karel Jaromir Erben and Bozena Nemcova.

Of course, we won’t be listening to any of these. (We’ve treated Rimsky and Dargomizhsky in the past.) Instead, we’ll have a flute sonata from 1882, by Carl Reinecke, which bears the subtitle “Undine,” an allusion to a novella by Friedrich de la Motte Fouqué, which was very popular among the Romantics. Fouqué’s Undine tells the tale of a water spirit who marries a knight in order to gain a soul.

Then we’ll hear the complete ballet, “Les Sirènes,” from 1946, by Lord Berners. Berners, notorious for his sense of the absurd (a horse was a regular guest at his indoor tea parties) was a talented composer, writer and painter. “Les Sirènes,” on a scenario devised by Frederick Ashton, features mermaids combing their hair and singing on rocks at a seaside resort, where sirens of another sort behave coquettishly on shore.

That’s “Come on in, the Water’s Fine.” PLEASE NOTE: Due to the egregious length of the Sunday opera (Wagner’s “Parsifal,” beginning at 3 p.m. ET), “The Lost Chord” will begin one hour later than usual, at 11. The repeat will air Thursday at the same time.

You don’t want to be out walking during Rusalka Week anyway, so why don’t you stay indoors and enjoy the show? Or listen to it later as a webcast at http://www.wwfm.org.