Just how good is John Millington Synge?

There's no doubting his importance. A century ago, he made modern Irish drama Irish, mining ethnic Irish life for the characters, culture and turbulent, expressive language that had been bypassed by his immediate Anglo-Irish predecessors, Wilde and Shaw, who sought success on London's terms.

Synge created a great national drama. But he did it as much by stance as masterworks, of which he left only one. He took the caricature of Ireland and gave it a robust life that pushes past condescension to reveal imaginative heart.

But given the treat of seeing one full-length and six short plays, staged as the Synge Cycle by Pittsburgh Irish & Classical Theatre, we discover that some are richer in intention than achievement. Program C, the final pair of one-acts, is a clear case of both falling short and breaking through.

Indeed, the angry tumult that greeted his greatest play, "The Playboy of the Western World," was not just boorish nationalism. By refusing to sentimentalize the noble Irish peasant, Synge plays a touchy double game, satirizing while he sympathizes, one sometimes looking suspiciously like the other.

Of these two plays, at 45 minutes "The Tinker's Wedding" is an instructive example of humor of character that ends up looking close to what it mocks, in spite of its verbal riches. But "The Shadow of the Glen," even shorter, shows how deeply into the heart -- and art -- Synge could penetrate. It joins "Playboy" and "Riders to the Sea" as his third masterpiece.

"Tinker" finds a scruffy trio of tinkers -- gypsies, we might say; wanderers -- scraping out a living on the road. Suddenly Sarah (Derdriu Ring) decides she'd like to marry Michael (Jason McCune), though marriage is a nicety tinkers hold in variable esteem. Michael is willing to do the deed, for fear she'll find someone else, though his mother, Mary (Bridget Connors), is suspicious, and the local priest (Philip Winters) thinks the whole business beneath contempt.

Sarah seems as motivated as much by whim as desire for stability, since stability isn't a tinker virtue. (Ring is visibly pregnant, which suggests another motive not in the text.) But the priest has to be bribed to perform the rite, and money is short. Then Mary drinks up part of the fee, and the plan turns into a battle between tinkers and priest.

What starts out as a cartoon of fecklessness, almost like an English sneer at the Irish, suddenly gains purpose. In opposing the narrow, pompous priest, the tinkers, the playwright and the audience celebrate robust life over bigotry.

There's also an interesting implied debate on marriage. But in spite of that and good character work under the direction of Andrew Paul, the result is more sketch or genre painting than substantive play.

"Shadow," however, is a great play. I haven't seen it for nearly 50 years, but it came back with a rush. A woman (Ring) is sitting by the unlamented corpse of her elderly husband (Jon Farris). A tramp (Martin Giles) arrives, seeking shelter. He has the gift of gab, and the wife leaves him to find a young farmer (Ben Blazer) with whom she may have some sort of understanding.

But things are not what they seem. "Shadow" is sort of a funny ghost story but mainly a poignant comic meditation on what matters most, comfort or passion, the pragmatic or beautiful. It's all about marriage and mortality. The wife has three choices. I think she chooses for the best, but you'd have to decide that for yourself.

It's also rich in analogies in myth, folklore and literature. It's no accident in the immediate wake of the revolutionary Ibsen's "Doll House" that the wife is named Nora and has to decide whether to slam the door on the way out.

Sheila McKenna directs with delicacy, aided by striking visual moments (a colored sky, figures in silhouette, a persuasive single candle). Ring is moving, if a bit dour, as the seeking wife, and Giles' Tramp is persuasive and poetic without excess, as in this:

"We'll be going now, I'm telling you, and the time you'll be feeling the cold, and the frost, and the great rain, and the sun again, and the south wind blowing in the glens, you'll not be sitting up on a wet ditch, the way you're after sitting in this place, making yourself old with looking on each day, and it passing you by."

In his welcoming speech, Paul addressed the complaint of some that they find the Irish accents difficult by announcing that texts of most of the plays are available on the PICT Web site -- a elegant response, I think.