There is a grand new organ in town. It is a Casavant of 3,364 pipes and 60 ranks, and it gave its inaugural concert yesterday afternoon at the Foundry United Methodist Church. The expert organist who also supervised the installation and design was Eileen Guenther, who presented a program to demonstrate the instrument's capabilities to the SRO audience. It was an immediate success; the organ is a knockout.

The instrument will not please the Baroque purists, and it will not suit those who want their organ soft and mellow. It is an organ that is orchestral in feeling but possessed of great clarity and definition. It is without question the right instrument in the right place, fitting its acoustic surroundings and open to the great bulk of organ literature and choral accompaniment. Combining 18th- and 19th-century organ concepts, it comes out of French tastes. It speaks evenly and robustly. The reeds are nasal and sassy; the mixtures are big and resonant; the flutes and strings are soft but not cloying.

Guenther showed the courage of her conviction and a good sense of the appropriate. She chose this organ and its specifications thinking of long-term function rather than bending to short-lived taste. Foundry Church, thanks to Guenther, has given a valuable addition to the Washington organ collection. The music she performed showed the value, ranging from Bach and Daquin to Franck and Durufle'. In every piece the organ met the intention of the music, going beyond it often with a distinct and rich sound.

Guenther is a dedicated organist who sees the organ as both a king of instruments and as a cooperative member of an ensemble. That totality of view comes through in her performance. She plays as a Kapellmeister, the musician as a part of the community. That makes for good music and an even better community.