Musical theatre has been publicly buried and excavated so many times, one must forgive the cynic who thinks each grave pronouncement little more than an excuse for the next one. What's particularly frustrating about the self-perpetuating cycle — more than the strained caterwauling over the jukebox musical or the messianic praise for a performance no better than several others in the same season — is how little room is left for steadfast brilliance. Yet there must be a place for someone like playwright-composer-performer Rinde Eckert, in whose Horizon — currently making its New York debut at NYTW — one finds meticulously obeyed that most basic and yet oft-overlooked command of musical theatre writing: Suit the music to the moment.

Working without a dominant style here, Eckert offers a panoply of compositions with sufficient internal coherence to avoid mere pastiche. His pieces lack insistent choruses — so call them new music, opera, or whatever you will — but they are expertly crafted and never less than dramatic. For the unheroic servants of God, we get a barbershop trio; for the destruction of a wall, snatches of an aria; for the giddy dreaming of two builders, a showbiz number.

These two builders (excellently played by David Barlow and Howard Swain) are allegorical — and aware of that fact. They are characters in Foundation, an unfinished play in several unofficial acts, the creation of minister Reinhart Poole (fervently sung by Eckert and inspired by the theologian Reinhold Niebuhr). Short of bricks, the masons must forever tear up part of their foundation in order to form another.

The shabbily dressed pair are a Gogo and Didi for a world in which God may be doubted but indeed does exist — and we meet them at a time when Reinhart needs his creations as much as they need him. Recently dismissed from the seminary where he's been teaching, Reinhart is writing his final lesson over the course of one long night, wrestling with allegory and family memories and the fine line between the two.

Alexander V. Nichols' wonderfully complementary scenic design suggests a school of hard but not unpoetic knocks. Out of its basic elements — chalkboards mounted on easels, wooden planks on metal sawhorses, concrete blocks strewn about — director David Schweizer illustrates the evening with the sort of striking images that would lose their humanity if blown up with technical wizardry. Perhaps the most potent of these images are those along the eternal road. There, in the end, Eckert/Poole marches off toward the horizon, facing truth and temptation, while so many linger behind, continuing to tear up and rebuild the foundations of church and the musical theatre.

Presented by and at New York Theatre Workshop, 79 E. Fourth St., NYC. June 5-July 1. Tue., 7 p.m.; Wed.-Fri., 8 p.m.; Sat., 3 and 8 p.m.; Sun., 2 and 7 p.m. (212) 239-6200 or (800) 432-7250 or www.telecharge.com.