"Lord have mercy . . . Christ have mercy" -- the words reverberated through St. Benedict the Moor Church in Northeast Washington as the 60-voice choir belted out the kyrie of the Roman Catholic mass in the rolling cadence and four-part harmony of black gospel tradition.

Clapping and swaying gently, the choir led the 400 parishioners from the "Lord have mercy" through the offertory and communion and finally to the recessional hymn -- a finely threaded blend of Afro-American and traditional European worship.

The "gospel mass," as it is called, is a fixture at several black parishes in Washington. But when Pope John Paul II comes here Oct. 7 to celebrate his historic outdoor mass on the Mall, there will be no gospel singing -- no uniquely black cultural element -- during the two-hour service.

Leaders of the Secretariat for Black Catholics of the archdiocese of Washington contend it is symptomatic of the church hierarchy's historic tendency to ignore the substantial black Catholic population here -- about 20 percent of the archdiocese's nearly 400,000 Catholics.

Perhaps more important, secretariat officials say, even when the hierarchy wants black "input," it circumvents the secretariat -- the agency expressly established to handle black matters -- and consults instead with a coterie of trusted hand-picked black insiders.

"It's a plantation mentality -- they got their house niggers and their field niggers," said Robert (Robbie) Robinson, a member of the Black Secretariat's board of directors.

"It's a case of the chancery [archdiocesan headquarters] still trying to live in the feudal days and their failure to recognize that blacks can make a unique contribution," said secretariat director Jacqueline Wilson.

Not so, say archdiocesan officials. Blacks are accorded appropriate recognition, they say, and to facilitate this, the black secretariat has direct access to the chancery, including regularly scheduled meetings with Cardinal William Baum.

As for the pope's visit, chancery officials say they have purposely included numerous blacks in the planning process and in "high visibility" ceremonial roles in the two-hour mass on the Mall next Sunday.

"It may not have been enough or the way they wanted it done," said Msgr. Raymond J. Foley, cochairman of the papal visit planning committee, "and we must always try to be sensitive to that."

With such a massive and historic event, Foley said, "Everyone wants to be involved, all kinds of people . . . and naturally, people will be hurt if they feel they're being passed by."

As it is, other officials said, selection of planners and participants has required a delicate balancing act to include not just blacks but Hispanics, other ethnic minorities, women and lay representatives from widely different parishes and geographical areas of the archdiocese.

Several officials said that some misunderstanding and anger has erupted because the black secretariat expects all black appointments and other black-related matters to go exclusively through the secretariat while the chancery uses both the secretariat and independent black pastors and lay activists in the community to ensure fuller and more diverse points of view.

Some chancery veterans are less charitable. Privately, they view the secretariat, a 23-member body elected by black parishioners in the archdiocese, as a group of chronic complainers and thus prefer to rely on a small group of trusted blacks outside the secretariat.

Even so, the secretariat has had some limited hand in preparations for the papal visit. The black family it recommended to help present the communion gifts to the pope during the mass on the Mall was selected by Cardinal Baum over more than half a dozen other black family candidates. It was also asked to furnish 14 black ushers for the stage area immediately surrounding the altar on the Mall and to nominate one black each for three major planning committees.

However, two of the three blacks say they were never contacted about being on a committee after their nomination last August. The third said he was invited to join but missed the first meeting because of a conflicting engagement and has not heard from the committee since.

In contrast, several other blacks have been appointed to key committees, but they were picked directly by the chancery and committee chairmen and not funneled through the black secretariat. These include two members of the key 20-member liturgy planning committee, headed by the Rev. W. Ronald Jameson. Also, five of approximately 14 Mall site planning committee members responsible for transportation, ushers and marshals are black, according to Jameson.

As for gospel-style singing at the mass on the Mall, black secretariat director Wilson said she and others suggested a single gospel selection in conversations with several high ranking archdiocesan officials, including the cardinal.

"We never received a request from the black secretariat," said Jameson, adding that he could recall no chancery officials mentioning such a suggestion to him, either.

"That's just it," said Wilson. " . . . No channels were set up. There is no official way of saying anything."

The point may be moot. Jameson said. While there will be no gospel singing during the mass itself, a selection of Afro-American singing will be included in a two-hour premass medley of ethnic religious music provided by the Smithsonian Institution's Folklife Festival. The music, scheduled from 11:30 a.m. to 1:30 p.m. near the altar on the Mall, will include Bessie Jones and the Georgia Sea Island Singers, as well as groups singing Jewish, Moslem, Hispanic, native American, Appalachian, Russian-American and Italian-American selections.

Jameson contends blacks will be well represented in various roles at the mass on the Mall. A compilation of black functionaries shows this pattern:

A black woman as one of two lectors. She will read a selection from the New Testament. The other lector, who will read from the Old Testament, is a white man.

A black layman as one of seven readers of general intercessions. His reading will be in English. The other six represent foreign language communities in the Washington area and will read their intercessions in Korean, Italian, Spanish, Vietnamese, Polish and French.

A black family to join a white family and an Hispanic family in presenting the gifts -- bread, wine and chalice -- to the pope for communion.

Two black deacons among three deacons to assist the pope in preparing the communion for consecration and carrying the cross at the opening and closing processionals of the mass.

At least one black seminarian among six to act as servers and to carry the Bible and candles at the altar.

One black among six masters and assistant masters of ceremonies.

The Most Rev. Eugene A. Marino, black auxiliary bishop of Washington, one of up to 19 bishops and archbishops to concelebrate the mass with the pope.

"A substantial portion of blacks" among 150 specially selected worshipers to receive communion directly from the pope. Msgr. Raymond J. Boland, cochairman of the papal visit, said most of the 150 are "not VIPs but what we sometimes call the 'little people,' people chosen for their long years of service to the church."

A small but undetermined number of black priests and deacons as part of 1,500 students with distinctive armbands acting as "sing posts" to help the eucharistic ministers position themselves in the crowd.

Several hundred black ushers and marshals among the 4,000 to 5,000 drawn from the 128 parishes of the archdiocese.

An undetermined number of blacks in the 500-voice primary choir and 1,000-voice backup choir drawn from area universities, including predominantly black Howard University, and from numerous parishes, including "several" black parishes, according to chancery officials.