From the soft, opening strains of Scott Joplin's "Maple Leaf Rag," it was clear that the New England Conservatory Ragtime Ensemble intended to impress last night's near-capacity audience of 5,100 at Wolf Trap with its captivating mastery of the ragtime idiom.

Offering a program that conductor Gunther Schuller called a cavalcade of ragtime, the 16-piece group demonstrated that rag can be an enormously engaging orchestral music-serene and bombastic, funny and sad.

The ensemble was well drilled. It performed Joplin pieces like "The Paragon Rag" and "Solac" precisely without being mechanistic. It also paid close attention to shading of color and tone, which made the overworked "Maple Leaf Rag" come alive with zestful freshness.

The program, however, wasn't only made up of Joplin rag. There were pieces by Tom Turpin, James Scott, Arthur Marshall and Eubie Blake - and most of them successful. Schuller also introduced Kenneth Laufer's "The Twelve-Note Rag," a piece based on the classical tone in which he combined a catchy melody of yesterday with contemporary harmonies.

The evening wasn't devoted entirely to rag. Schuller led the group through three rousing Jelly Roll Morton jazz pieces and two James Reese Europe combinations written for the dance team of Irene and Vernon Castle shortly before World War I.

Schuller's introductions to each composition mounted to a fascinating lecture on the development of American popular music in the early part of the 20the century. He should take his talk on the road.