If City Council Member John Ray (D-At Large) runs for mayor, as many in the city predict, he won't have to go far to court voters. And he won't have to go far to vote for himself, either -- just out the back door of his home, across the alley and into the polling place at Bertie Backus Junior High School.

Last week, Ray -- who is fond of calling himself the only renter on the City Council -- signed a contract to buy half of a neat, brick semidetached house on 7th St. NE in the heart of outsized Precinct 66, which is located in Ward 5.

Ray said earlier this week that it was "just a coincidence" that he chose a house in the city's largest polling district (with 3,733 registered voters last year, 3,384 of them Democrats) so close to the start of the 1982 mayor's race, in which he is expected to be a participant.

A Ray adviser noted, however, that while the choice of precinct might have been coincidental, the choice of ward was not. Like the other contenders for mayor, Ray will make an intrensive pitch for votes in the Ward 5 neighborhoods where former mayor Walter E. Washington always did so well.

With Washington not in contention this time, the current political wisdom is that the former mayor's supporters constitute fertile ground, available for cultivation by an astute candidate.

Ward 5 covers Northeast Washington from the B & O Railroad tracks eastward to the Anacostia River and from the Maryland line south to Florida Avenue. It is largely a residential area lined with neat cottages and duplexes like the one Ray is purchasing.

The predominantly black ward has seen little of the influx of younger black professionals that has taken place, for example, in parts of Ward 7 across the Anacostia, where Barry moved. Instead, Ward 5 remains the home of Washington's backbone black population, the civil servants and retirees who live modestly and quietly.

The black Baptist churches in Ward 5 are considered a focal point of the area's politics, and Ray, probable candidate Sterling Tucker and Mayor Marion Barry all have designs on the churchgoing crowd.

Ray says he is buying the house because of his forthcoming marriage to Sarah Lash, an employe in the Amtrak personnel office. She doesn't want to live in his Capitol Hill apartment in Ward 6, he said. "That's the only house I can afford."

Robert Gill, director of the famed Cardozo High School marching band that strutted through the streets of Pasadena in January's Rose Bowl Parade, has resigned his job, effective Friday.

D.C. Acting Schools Superintendent James T. Guines said Gill submitted a letter of resignastion on May 14, explaining that he was leaving to take "a position with private industry." Gill could not be reached for comment on his decision to leave.

"He's an awfully fine person, and he's generated a lot of excitement with the Rose Bowl trip," Guines said. "Often, it's just hard for us to keep good people."

Potential candidates for mayor and council chairman are attending all the community functions they can. Recognition, after all, is crucial. But it's not always forthcoming.

Last week, at Barry's Ward 6 town meeting, the mayor was introducing the coterie of city officials he had brought along when At-large Council Member Betty Ann Kane, a Ward 6 resident, dropped in and took a seat at the head table. Barry looked down the long table, introducing his officials one by one.

Seated at the end of the table was Dane, who is mentioned as a possible candidate for either top office and who had sparred with Barry earlier in the day, accousing him of a "sneaky" attempt to circumvent home rule.

Barry got to the last bureaucrat before Kane and then went on with his introductory remarks, leaving Kane to smile grimly. Unrecognized.

A month earlier, Kane had been among several council members who attended the groundbreaking banquet for construction of a new $2 million building for Metropolitan Baptist Church. The presence of each of the council members was acknowledged from the podium. But Kane had arrived late, and the evening's master of ceremonies didn't recognize her when she came up to take her seat at a front-and-center table.

So Kane handed a note up to the dais. Moments later, she was introduced for a bow. The contents of the note were not divulged.