Johannesburg — Black political dissent, on a national scale, is finding its voice again in South Africa. The voice is often at odds with itself, expressing conflict and confusion within the black community. But it is robust and lively - and a far cry from the relative silence that followed the Soweto riots of 1976 and the state crackdown on black activism that ensued.
What is emerging is a black struggle to forge broader political opposition to South Africa's white minority government out of the splintered, narrow-interest black pressure groups that filled the void in the post-1976 period. The hope is to do so openly rather than from the underground - yet without compromising black interests by participating in institutions ''tainted'' by government links. Such suspect institutions include local community councils or ''homeland'' authorities.
Oddly enough, the South African government deserves some of the credit for the resurgence of black activism. Its so-called ''reform'' policy of bringing Coloreds (persons of mixed-race descent) and Indians into the now all-white Parliament, while still excluding the black majority, has galvanized government opponents into action.
At the same time, the South African government is giving its opponents slightly freer rein. Orders banning political activity have been lifted on all but 11 persons, detentions have slowed, and former prisoners arrested under the security laws have been allowed to get involved openly in black politics.
Pretoria's greater measure of tolerance is apparently meant to underscore to a skeptical West - and its own local critics - that it is sincere about reform.
Later this month, a relatively new group called the United Democratic Front (UDF) will launch a nationwide campaign to defeat the government's ''reform'' proposals. Although the UDF is multiracial, it is primarily black in membership and orientation. It sees the ''reform'' initiative as a government strategy to divide and weaken nonwhite opposition.
The UDF is one clear sign of the new forces coming to the fore in internal black politics. Political analysts regard it as the first broadly based, national black pressure group to emerge since the upheaval of 1976. (The dominant black political group in recent years has been the banned African National Congress (ANC), which carries out cross-border guerrilla raids against South Africa.)
There are plenty of other actors on the local black political scene, but most have narrower bases. Gatsha Buthelezi's Inkatha movement is large but confined mainly to the Zulu tribe. Black trade unions have for the most part focused on worker issues. And new civic associations have been concerned primarily with local matters.
The Azanian People's Organizaton (AZAPO) - the main survivor of the black consciousness movement - is technically a national political group, but most analysts say that in practice it has a fairly narrow ideological base of support.
Indeed, AZAPO is one of the groups trying to broaden and unify black political dissent. AZAPO leaders organized a meeting of a number of black organizations in June - together called the National Forum (NF) - to begin forging greater unity among black activists. One of the main motives was to combine forces in opposing the government's ''reform'' proposals.
However, the UDF appears the leader in trying to unify sectional black interests. When it officially begins its campaign later this month, it will already claim an impressive list of affiliates that include trade unions, civic associations, student groups, women's organizations, and religious bodies.
The UDF is vague at this point on what its strategy for defeating the ''reforms'' will be. The government has promised to put the proposals before white voters in a referendum, and to test opinion in some manner in the Colored and Indian communities.
A UDF spokesman said the organization's main thrust would be ''education of the people'' and insuring they do not ''fall for the government propaganda.''
The UDF seems to spring from the powerful tradition of the Freedom Charter - a document formulated in 1955 at a convention that included black, Colored, Indian, and white political organizations. It called for a nondiscriminatory, democratic South Africa.
One of the groups accepting the Freedom Charter was the African National Congress. As a result, ''charterist'' organizations are today perceived to be in support of the aims of the ANC, if not the group itself.
Leaders of the UDF are for the most part strong supporters of the Freedom Charter. And the group says the political alliance that was forged in the 1950s is the precedent for its own strategy of forming a united political front against the government.
However, the UDF insists that as an umbrella organization it is open to all types of groups and individuals, not just ''charterists,'' a claim upheld by its membership list.
The UDF has grown rapidly since the idea was put forth early this year by Colored theologian Allan Boesak, partly because it has operated unimpeded by the state.
However, UDF leadership has already been hit by government action. Mrs. Albertina Sisulu, wife of imprisoned ANC official Walter Sisulu and president of the UDF in the Transvaal province, was arrested recently, charged with taking part in ANC activities.
Most observers here reckon the critical phase in UDF-government relations will come when the new group embarks on a program of action.
Many analysts have looked on the convening of the National Forum subsequent to the founding of UDF as reflecting the desire of forum members to provide a black consciousness alternative to the UDF. However, both efforts might be seen more accurately as attempts to move beyond sectional interests.
The organizers of the National Forum and the UDF have eyed each other warily, without openly condemning one another. But few organizations participate in both , and there are as yet no signs the two groups are overcoming their ideological differences.