For Mozart’s 250th-anniversary year, the Salzburg Festival set out to do all 22 of the composer’s stage works, and they are. But they combined two of them: “Bastien und Bastienne,” written when Mozart was 12 (yes, 12), and “Der Schauspieldirektor,” or “The Impresario,” written when the composer was an old man of 30. Was that cheating, putting two together like that? Maybe, but it worked out okay.

“Der Schauspieldirektor” is about — whaddaya know, an impresario, and in this production he put on “Bastien und Bastienne.” So we had an opera within an opera, or one opera that framed another. I was skeptical of this blending — the work of German director Thomas Reichert — and would have preferred to see each opera on its own. But, to repeat: This worked out okay.

This was not the first time the Salzburg Festival had staged “Bastien und Bastienne” (although the blending was, of course, novel). The Festival had done it as far back as 1928, eight years after Max Reinhardt et al. founded this affair. And the Festival had last done it in 1970, with a cast that included Ileana Cotrubas and Agnes Baltsa — not bad. As for “Der Schauspieldirektor,” the Festival did not get around to doing that until 1976, and had last staged it in 1991.

Both operas are examples of “singspiel,” the Germanic tradition that Mozart apotheosized in “The Abduction from the Seraglio” and, especially, “The Magic Flute.” We don’t have really famous music from either “B&B” or “Der Schauspieldirektor,” except for the overture to the latter, one of Mozart’s C-major rousers. (The overture to “The Abduction” is another.)

The combined operas this year were performed in … the Marionette Theater, one of Salzburg’s most celebrated and beloved institutions. In fact, the joke around here for many years has been that the best Mozart productions are found with the marionettes — that’s how screwy the productions in the big, human houses have become. Frankly, that is not really a joke (vide “The Abduction,” in the Festival’s House for Mozart).

Director Reichert duly used those marionettes, but he also used flesh-and-blood singers, who kind of lurked near the orchestra. They engaged in some acting, although you were supposed to look at the marionettes on the stage, I suppose. In any case, the singers were on the young side, and associated with Salzburg’s Mozarteum, which is only steps from the Marionette Theater.

Sunday night’s performance — the last of the summer — was focused and lively. Outstanding among the singers was Bernhard Berchtold, an Austrian tenor. He sang beautifully, intelligently, and easily, with a very secure technique. The world never has enough Mozart tenors, and we should happily welcome this one.

Two sopranos were on offer, one a Pole, Aleksandra Zamojska, and the other a Greek, with the marvelous name of Evmorfia Metaxaki. Ms. Zamojska was sincere, unaffected, and appealing, and she handled her coloratura pretty well. She went up for several high Fs, grabbing madly at them and sort of strangling them, but achieving them. Ms. Metaxaki was bright of sound, and bright of manner, too. She seems to have many, many operatic tools. And she took notable pleasure in her singing — which is one of those tools.

A low voice in this mix was Radu Cojocariu, a Romanian bass. He was both sturdy and smooth. Incidentally, it was nice to hear a Pole, a Greek, and a Romanian — all adoptive Salzburgers — chattering away in 18th-century singspiel. The world, certainly Europe, can seem quite small.

The orchestra was also full of Mozarteum folk. This was the Salzburg Youth Philharmonic, founded in 1998 by a (young) Austrian conductor, Elisabeth Fuchs, who led the performance Sunday night. Her orchestra was not especially refined or accurate, but it had clear dedication and exuberance. Mozart has a good time, and he wants you to have a good time, too.

Just a couple of notes, to end on. I wonder whether the microphones were necessary, for singers, instrumentalists, speakers, or anybody. Much of the evening seemed overloud, and the theater is fairly dinky. Last, it was lovely to hear a little girl’s laughter peal throughout that theater, as the marionettes did their tricks. I doubt she was much younger than Mozart was, when he gave us “Bastien und Bastienne.”

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When he was 15, Mozart wrote “Betulia Liberata.” It is not exactly an opera, more like an oratorio — more specifically, an “azione sacra,” or sacred action, in two acts. Mozart wrote it on a text of Metastasio, the master of opera seria. And that text is from the Book of Judith, which belongs to the Apocrypha.

The story tells of “Betulia liberated” (as Mozart’s title has it). What happens is basically this: The Israelite town of Betulia is under siege by an Assyrian army. All seems lost. But Judith, a widow, has a plan. She goes into the enemy camp, makes nice with the leader, and returns with his head — I mean, literally.That’s it, in an extremely tight nutshell. The piece, true to its form, gives you recitative and aria, recitative and aria, at length. It may not be Mozart’s most inspired work, but it is still Mozart, and not at all bad for a mid-teenager (or for anybody).

The Salzburg Festival presented a single performance of “Betulia Liberata,” with no staging. The concert took place on Friday night in the Felsenreitschule, in front of that multi-tier parking garage that serves as the set of “La Clemenza di Tito.” The orchestra was a good one: the Munich Chamber Orchestra, led by a good conductor: Christoph Poppen. Mr. Poppen, a German, has been music director of this group for 11 years; his tenure will come to a close at the end of this season.

He conducted “Betulia” both energetically and beautifully. The orchestra played with “period” zip, but did not scant tenderer aspects. You don’t get this from every such ensemble.The chorus was the Concert Choir of the Vienna State Opera, who were balanced, on pitch, and feeling. Verdi and Saint-Saëns would both go a little nuts with Israelite choruses; Mozart (among others) was there before them.

Judith, or Giuditta, in the text’s Italian, was something unusual: a contralto, proving that this species is not quite ready to join the dodo bird.She was Marijana Mijanovic, a Serb, with a dusky, husky, arresting voice. I’m not sure you’d call it a beautiful voice, but it is maybe something better than beautiful: interesting, making you listen.And she knows what to do with this unusual instrument, musically and theatrically.

In the role of Ozia — a leading one — we were to have Rainer Trost, the well-known German tenor. But he was absent, for reasons unstated, replaced by an English tenor, Jeremy Ovenden. Mr. Ovenden showed himself to be a peppy, springy, agile singer, with a little quiver in his voice — a slight bleat. His top notes could be pinched, but this was no great problem. Mr. Ovenden more than filled the bill. Some of his recitative singing, in a half voice, was really lovely.

Other singers? Julia Kleiter, a German soprano, was poised and elegant. Franz-Josef Selig, a German bass, was warm and strong (a desired combination). Jennifer Johnston, an English mezzo, was perfectly appropriate. And Irena Bespalovaite, the Lithuanian soprano, took time off from portraying An Old Wife/Papagena in “The Magic Flute” to take part in “Betulia.” She is a clean, pure lyric soprano who is not without some vocal heft, which is nice.

I can’t tell you that I am in a great, great hurry to hear Mozart’s “sacred action” again. But do not doubt the greatness of the piece: It is eminently excerptable, at a minimum.

Until August 31 (for more information, call 011-43-662-8045-500).