The names on the program for the Groupe Vocal de France's intriguing Saturday night recital at the Folger Library were considerably more familiar than the works. The conductor was the redoubtable English choral director John Alldis.

The unaccompanied Groupe is a trailblazing organization of 12 singers established seven years ago by the French Ministry of Culture to explore the repertory of vocal chamber music--a category neglected by composers from the post-Renaissance period to the present. Thus the most familiar work on the Groupe's program was the oldest, a madrigal called "Psaume de Penitence No. 5" by the 16th-century Flemish giant Orlande de Lassus (listed on the program by his alternate first name, Rolande), given a beautifully thought-out, if tonally rough, performance.

It is an irony that but for the revival of the madrigal and its related musical forms, especially by Nadia Boulanger in Paris, the repertory for unaccompanied vocal works might still be dormant. But the new-found popularity of Lassus and Monteverdi--to name just two of the most obvious composers--has led to the formation of more groups equipped for this music, and thus to the commissioning of new works.

There were two of these Saturday night, one a brief and striking madrigal for five voices by the Italian Girolamo Arrigo that recalled the experiments with sonorities by Gyorgy Ligeti, with much of the text in wordless sounds. The work was introduced with bell-like repeats of the same note at irregular intervals, gradually melding a sustained hum on the same note. The contrasting central section was similar in principle, if not at all in sound, to the madrigal tradition, as the webs of solo voices interlocked into the most complex polyphony--all of it repeatedly seeking some kind of tonal harmonic resolution, only to have each attempt by one voice undercut by a slippage from another. It is a good work, made even better because it is concise and brief.

The next composition, "Cris" by the contemporary Frenchman Maurice Ohana, was just the opposite--obscure, inflated and shallow. It was, literally, a series of different kinds of cries, evoking aspects of the Holocaust and divided into five movements that went on for more than 20 minutes. The idea seemed to be to exploit as many kinds of semi-musical lip, nose and throat sounds--occasionally accompanied by little hand cymbals--as the 12 singers could summon.

The encore was the most powerful work on the program, Arnold Scho nberg's last work, a brief psalm written in 1948 for the founding of the state of Israel. If the Ohanas of the world want to know how to make a meaningful statement about human suffering they might turn to the father of atonal music. Lasting no more than five minutes, the psalm has immense power, growing out of the most concentrated compositional and emotional tension. It is not easy music, but it is very much worth the listener's concentration.