Oscar Straus (note the single “s”) may be considered the last of the Viennese operetta composers. Best known internationally for The Chocolate Soldier (1908), he made his fortune in Europe a year earlier with the sugary, schmaltzy A Waltz Dream. Straus, who also wrote the score for the film La Ronde, died in 1954.

Lyric Opera San Diego offers a few more performances of the rarely heard A Waltz Dream at the Birch North Park Theatre, directed by J. Sherwood Montgomery.

Set in a mythical European country just before World War I, Princess Helene (Laura Parker) has just married Lt. Niki (Chad Hilligus) of the Austrian army, who had served as Helene’s escort while her father King Joachim (Walter DuMelle) was off on a state visit.

But Niki is having second thoughts and, despite many pointed comments about continuing the royal line, Niki deserts Helene on their wedding night for the closest wine garden, where he is captivated by Franzi (Stacey Stofferahn), conductor of the all-girl band performing there.

Fear not, there’s no intrigue, betrayal or treachery. Remember, this is operetta, and a happy ending is required. A Waltz Dream boasts nice if mostly unmemorable music, good singing and the aforementioned ending.

The theater continues to have the problems I always complain about: lack of raked seating, no supertitles (especially needed in shows like this that almost no one has seen), and bad sound made worse by sound-deadening, fabric wall coverings.

But the principal voices are fine (Stofferahn a particular favorite), and the joy of hearing an unfamiliar piece may be enough to overcome the theater’s sound shortcomings and Montgomery’s high-schoolish direction.

A Waltz Dream plays through Sunday, April 12. Shows Thursday and Saturday at 7:30 p.m.; matinée Sunday at 2:30 p.m. For tickets, call 619-239-8836 or visit www.lyricoperasandiego.org.