D.C. City Council member John Ray, who already has spent $55,000 on a snappy, two-week radio campaign to boost his candidacy for mayor, will spend $3,500 more next month to advertise on the sides of 35 Metro buses.

Ray, who became the first Democrat formally to enter the race on Jan. 9, has spent more than a third of the $140,000 he's raised so far on media advertising--an early-bird strategy that has no parallel in D.C. mayoral politics.

The advertising campaign was designed to set an upbeat tone for Ray's candidacy and to increase name identification, according to campaign aides. More than 60 percent of the likely voters interviewed by Ray pollsters in June said they didn't know who Ray was.

"I think we'll find that the ads really helped," one of Ray's campaign advisers said Friday. "There's no way you can run a campaign on jingles, especially in this market. But it helps our name ID and it will help when we start going door-to-door."

Dan Pero of Bailey, Deardourff and Associates, the political consulting firm hired to assist Ray in his campaign, said the jingle featured in the radio campaign that began Jan. 9, "This Man, John Ray," was written by Nashville composer-arranger H. Jackson Brown Jr. Pero said it was designed as much to appeal to community pride as to make a campaign pitch for Ray.

"The feedback has been nothing but positive," Pero said. "People like the song. They're singing it."

Bailey, Deardourff has used jingles in other campaigns it has advised, with varying degrees of success. For instance, the firm advised former attorney general J. Marshall Coleman, a Republican, to use a similar jingle in his unsuccessful gubernatorial campaign in Virginia. The song said, in part, "We've got a good thing going, let's keep a good thing going."

Pero said the campaign posters that will be plastered on the curb side of Metro buses beginning Feb. 1 are designed to reinforce the message of the radio ads and convey the impression that Ray's campaign is on the move.

For those who prefer cars to public transportion, Ray supporters will mount a campaign blitz at many of the city's full-service gasoline stations.

The Greater Washington and Maryland Service Station Dealers Association, angered by Mayor Marion Barry's sponsorship of a short-lived 6 percent gasoline tax that they say drove some dealers out of business, is expected to endorse Ray this week.

Ray, a lawyer and one-term council member, sought the nomination for mayor in 1978, announcing his campaign 11 months before the primary. But the campaign never took hold. Ray could not afford an early advertising drive and the lack of funds eventually prompted him to drop out of the race. He wound up supporting Barry.

At the time, Barry was a well-known, at-large council member and former president of the school board. He launched his campaign on Jan. 21, but delayed his radio and TV commercials until the following August as an economy measure.

The other two major candidates, incumbent Walter E. Washington and former City Council chairman Sterling Tucker, didn't formally enter the race until late April of that year. Tucker retained Bailey, Deardourff that year as his political consultants and waged a high-priced television advertising campaign that began in June, well before the other candidates.

Barry is expected to announce soon his plans to run for a second four-year term. Several other prominent Democrats, including former Carter administration Cabinet member Patricia R. Harris, and council members John A. Wilson, Betty Ann Kane and Charlene Drew Jarvis, have also expressed interest in challenging Barry, along with Tucker. The Democratic primary is scheduled for Sept. 14.