What did Willy Loman sell?

When "Death of a Salesman" opened, that became a preoccupying, if irrelevant, question. Even Fortune magazine had a long, discursive essay on a matter Arthur Miller had ignored in favor of a wider symbolism.

Drama began with the gods and spirits, worked its way down to kings, princes and dukes. Inherited wealth was enough to feed dramatic characters. While theatrical luminaries, politicians (scrupulous or unscrupulous) and recognize the Century of the Common Man by concerning themselves with how the Common Man earns a living.

This concern, in fact, is common to four plays now in New York, plays that reveal ordinary people seeking to relieve their boredom with unsatisfying vocations.

In "Comedians," English playwright Trevor Griffiths gives us factory workers of Manchester taking night classes to become nightclub comics.

John Bishop's "The Trip Back Down" centers on a man who scorns Westinghouse job opportunities in Mansfield, Ohio, in favor of the dangerous, chancy celebrity of stock-car racing. These are among the few new dramas on Broadway this season.

Off-Broadway finds a newly revealed playwright, David Mamet, considering the lives of office workers and two retired gentlemen in "Sexual Perversity in Chicago" and "Duck Variations," known as "The Mamet Plays."

Moved from its established Second Avenue headquarters, the Negro Ensemble Company's "The Brownsville Raid" is continuing another month at Theater de Lys, where Charles Fuller's characters are blacks in Teddy Roosevelt's army of 1906.

In all these plays a general dissatisfaction with work propels the characters into other activities. With livelihoods uninherited, but thrust upon them, the characters' choice of what to do with their lives and leisure reveal vital facts about them. Focusing attention on what a play's characters do for a living is a comparactively recent development.

The most dramatic - and most helpless - of these are the men in the 25th Infantry regiment of 71 years ago stationed at Fort Brown, Brownsville, Tex. This is a slice of forgotten history as revealing of the black misery as "Roots."

Around midnight of Aug. 13, 1906, unidentified soldiers, angered at slights from white citizens, apparently slipped into town and shot into homes and at citizens indiscriminately, killing one man and wounding a policeman. In less than two months, the army completed an investigation without finding any incontrovertible truths. A 26-year veteran sergeant-major theorized that the whites fired the bullets themselves to suggest that they were attacked by black soldiers.

President Teddy Roosevelt ruled that unless individuals own up to their guilt, 159 privates and noncoms will be "discharged without honor from the army" because of their "conspiracy of silence." The old sergeant, satisfied in his own mind that the men had been used outrageously, prevailed on them to maintain silence. In Fuller's moving peroration a voice-over tells us of their subsequent, wasted lives. Their tragedy is that in those days, an army career was one of only a few roads to self-respect for blacks. Deprived of that, they were limited to laboring jobs of daily wages and unprotected old age.

Whether the men were guilty in Fuller's reconstruction is less important than how they were treated. They lost their livelihoods not because they were guilty, but because they were black.

There is a program note that "We are grateful to Lt. Col. Peter J. Barrett, U. S. Army, Office of Public Affairs, for his assistance," giving a tone of authenticity to the documentation. A broken promise by Teddy roosevelt to Booker T. Washington just before Election Day of 1906 is used to indicate base political motives. What the playwright avoids saying is that the Presidential election years for Roosevelt were 1904 and 1908, while 1906 was a congressional election year. The misleading balance, suggesting that Rooseveltacted as he did for white, purely political reasons, disturbs me. Fuller uses an untruth here to lead the audience to a false, wholly emotional, even dangerous, conclusion.

Though the play takes a dogged first act to set the situation, the two succeeding acts are strikingly good theater and under the direction of Israel Hicks, the NEC production is splendidly acted. Douglas Turner Ward is the old sergenant-major, Ethel Ayler, not long ago an active Washington actress, are among the very fine players the cast of 17.

David Mamet's double-bill of Chicago plays, deftly staged in fitting staccato fashion by Albert Takazauckas, are marvels of dialogue and rhythmic reflections of today's urban mores.

In "Duck Variations" ordinary park bench conversation by two oldsters about ducks - of which they know nothing - is curiously affecting as acted by Mike Kellin and Michael Egan. Despite its unsavory title, "Sexual Perversity in Chicago" is a deliciously amusing sequence of vignettes about two young men and two young women whose office and teaching jobs keep them alive for more amusing dalliances. The occupations carry over into their after-hours attitudes. Mamet pointedly avoids "the well-made play," but has achieved contemporary life with a wrenching tenderness. His characters are especially well defined and the players, F. Murray Abraham, Jane Anderson, Peter Riegert and Gina Rogak, are faultless. One prays that these will soon find a fitting, intimate Washington stage and six such aware performers.

Because of awkward staging in a distracting set and lumbering, dragged out situations, "The Trip Back Down" struck me as ersatz drama. Bobby Horvath is, in a sense, a Midwestern Willy Loman, misguided by ambitions that propel him to leave wife and daughter in pursuit of racing fame that never comes. Bobby's tragedy is that it's too late to go back and the play's is that it was not honed down before production.

Griffiths' "Comedians" suggests more than ever actually surfaces. Manchester, England, so vital as the milieu, seems more alien than most of the British midlands plays we've been admiring. I doubt that American audiences will find much involvement here because so much of the background is so unlike America, though Mike Nichols has staged it with his finesse.

Act I sets up the dissatisfied young men in their dingy classroom, learning how to make people laugh from an old comic. Act II shows their appearances before a working class club. Act III suggests that the most defiant of the hopefuls may be a genius and that Griffiths is urging the disoriented into independence.

But in focusing on what work means to workers, all four plays are striking reflections of playwrights' efforts to be relevants to today's work-conscious audiences. It's indicative that with their lightness of touch. "The Mamet Plays" are the most effective. While speaking up, they avoid the portentous and dare to amuse.