Playhouse Jr., the children's theater of Point Park University's Pittsburgh Playhouse, wraps up its season with two shows that hint at how broad "children's theater" can be -- and how much our understanding of it is has changed over time.

Commedia dell'arte is an improvisational form of street theater that flourished in Italy from the 15th to the 18th centuries. It used stock characters ranging from sappy lovers to tricksters like the patchwork Harlequin, whose namesake, Arlecchino, is this comedy's main character.

Commedia is fast, simple and funny, and it spawned puppet shows like Punch and Judy, so it would seem a natural inspiration for a piece of children's theater. But while this is the world premiere of a new "Arlecchino" that is meticulously acted and packed with historical information, it left me wondering whether commedia is such a good fit for kids, after all.

My doubts certainly aren't due to the cast. Director David Vinski has opted for a range of styles for his excellent cast, from highly stylized to almost naturalistic. While Brandon Gary Giles, who plays Arlecchino with a gliding, pointed-toe walk and a heavy "Italian" accent, is the most exaggerated, he also gives the best performance.

Also stylized are Aaron J. Amendola as the portly Dottore and Andrew Danowski as the silent, impish Pedrolino. All three actors deserve credit not only for mastering the exaggerated style but also for maintaining a connection to a modern, often young, audience.

Of the rest of the cast, Emily McVickers stands out for her sly humor as ballerina Margherita.

Playwright Yoli accurately represents commedia traditions, so "Arlecchino" is a series of mostly unconnected scenes incorporating humorous bits, or "lazzi," as well as songs and dances. It's worth noting, though, that the characteristic sexual humor and thumb-in-your-eye violence is mostly absent (and a good thing too, considering the very young children who attend).

While the technical skill of the cast and the historical background is great fun for those who know theater, it seemed over the heads of the young people in the audience. While they clearly enjoyed shouting "he's behind you!" during the trickster scenes, much of the humor seemed to escape them as well. As universal as jokes about someone who has "lost his ass" (Arlecchino's donkey, that is) may seem, the unfamiliar style of delivery means they don't always survive the translation.

"Arlecchino" remains a sprightly, educational show -- I'm just not convinced it's a show for children.

For as much as "Arlecchino" seems to not quite match its audience, "A Year With Frog and Toad" seems tailor-made for this crowd.

Based on Arnold Lobel's award-winning children's stories, Robert and Willie Reale's musical chronicles a year of the little pleasures (drinking tea, raking leaves) and the quickly forgotten disappointments (no mail, embarrassing bathing suit) that mark the friendship of the title characters.

Although "Frog and Toad" had a short Broadway run and can be enjoyable for adults, it is in all ways a children's show. This production expands the original five-person cast to 14 and pumps up the ensemble numbers, but it remains a musical about the small things in life that seem much bigger when you're small yourself.

And what child can resist a big production number that's all about eating cookies before dinner? "Cookies" is the show's best, although Rachel Dudt's mail-delivering Snail has some of the show's best lines in her "Letter" songs, including her boast that she puts the "go in escargot."

Again, the cast is uniformly very good, although Sawyer Armstrong's Turtle, who takes the lead in teasing Toad about that unfortunate bathing suit in "Getta Load of Toad," seems almost too mean for such a gentle show.

The three birds, played by Nick Ferrara, Kiley Caughey and Audrey Beauchamp, form an especially appealing bunch, rendering beautiful three-part harmony throughout.

John Wascavage plays the cranky Toad with just enough petulance to stay likable, and Justin Mark DeWolf stops short of treacly with his portrayal of the optimistic Frog.

The real stars of this show are Nathan Brubaker's set design and Meredith Murphy's costumes, which are nicely augmented by Scott Nelson's lighting and Brad Peterson's sound design.

Murphy wisely avoids realistic animal costumes, focusing instead on real clothes with organic-looking fabrics and patterns. Frog and Toad wear natty suits and vests with color-appropriate warts attached, while the Snail's shell is offset by spiral-patterned corduroy pants. The Moles wear brown argyle vests and the Lizard, a patterned green tunic and tights.

My only concern has once more to do with audience. Director Rodger D. Henderson keeps the show moving briskly, but at 90 intermission-free minutes, I'd argue "Frog and Toad" is about 15 minutes too long for the kids to whom it would most appeal.