Clifford D. Dowe, a former Washington music promoter who once helped provide entertainment for the Summer in the Parks programs and for the "Toys for Tots" Christmas benefits, was sentenced yesterday to serve three years in prison for possession of more than $10,000 worth of cocaine.

Dowe, 39, was arrested at his home in the Gold Coast neighborhood off Upper 16th Street NW in September 1978 by law enforcement authorities who had been told by an informant that Dowe was selling cocaine from his house, according to court records.

After a trial last November in U.S. District Court, Dowe was convicted on the cocaine charge and on two lesser charges for possession of small quantities of marijuana and hashish.

It was learned yesterday that various local political officials, including Effi Barry, wife of Mayor Marion Barry, City Countil Chairman Arrington Dixon and D.C. Del. Walter E. Fauntroy (D-D.C.) had written letters in behalf of Dowe to Judge Aubrey Robinson Jr., who sentenced Dowe yesterday.

Such character references are commonly submitted to judges prior to sentencing in criminal cases. Robinson, however, said in court he was convinced that none of those officials was familiar with the charge against Dowe.

"I'll bet . . . there's nobody who can convince me that Congressman Fauntroy knows about the facts of the case . . . Nobody told him that before he sat down and wrote me a two-page letter," Robinson told Dowe and his lawyer, former D.C. Superior Court judge Charles W. Halleck.

Robinson added, "Those are the same people who will get to the press and excoriate judges for slapping people on the wrist when they are dealing with drugs . . . the same people . . . "

At the hearing yesterday, Assistant U.S. Aorney Martin Linsky told Robinson that an agent of the Drug Enforcement Administration office in Baltimore was prepared to testify that the DEA had information that Dowe was a "major narcotics dealer." The agent did not testify, however, and Dowe repeatedly denied during the hearing that he was a drug dealer.

"I'm not a drug dealer, your honor. I'm simply not a drug dealer. I've made mistakes but I'm not a drug dealer," said Dowe, the father of three young children. His wife, Pregnant with their fourth child, was present in the courtroom yesterday.

At one point, the judge asked Dowe, "What do you think happens to people who sell dope. . . . . . . What did you think was going to happen . . . (that) you were going to get a medal for it?"

"No sir . . ." Dowe responded.

Robinson, obviously disturbed by the case, then asked Dowe, "Started your kids on it yet?"

Dowe again denied that he was selling cocaine. "Your honor, I have not been doing that for a living," Dowe said.

Dowe contended that the cocaine confiscated by law enforcement authorities at his home was bought from a source in New York for his own personal use; that it was a "one-shot deal" and that he "was not otherwise involved in drug sales in anyway," according to court records.

The government, however, said in the records that it had discovered information "concerning Mr. Dowe's serious involvement in local drug trafficking. . . ."

After the sentencing yesterday, Dowe's attorney Halleck filed notice with the court that the case would be appealed.

During the trial, Dowe did not deny that the cocaine had been confiscated at his home, but contended that he had purchased the drug in New York after he was pressured to do so by a police informant, his attorney Halleck said. After sentencing, Halleck appealed Dowe's conviction to the U.S. Court of Appeals yesterday.

Lynn Bumbray, an assistant to Effi Barry, said yesterday that Dowe's wife had asked Barry to write the letter to the court in Dowe's behalf. Bumbray said she actually composed the letter that generally said that Dowe had been a good father and husband.

Bumbray said that Effi Barry had known Dowe's wife for about four years and that Barry had helped prepare a list of guests for charitable Christmas parties that Dowe's wife arranged each year. Bumbray said that Barry knows Clifford Dowe only through his wife.

When she wrote the letter for Barry's signature, Bumbray said she did not know the details of the charge against Dowe. She said that the letter was requested by Mrs. Dowe at "the last minute out of desperation." Bumbray said she understood that Dowe claimed he had been "set up" for the drug deal.

A spokesman for Council Chairman Dixon said that Dixon had written a two-paragraph letter to Judge Robinson dated Dec. 19. The letter said that Dixon had known Dowe for "many years as a businessman and concerned member of the community," the spokesman said. Dixon also wrote that he was not familiar with all the details of the case, according to the spokesman.

A spokesman for Fauntroy's office said the congressman's letter in Dowe's behalf, dated Dec. 12, 1979, noted that Dowe and his wife had organized "Toys for Tots" Christmas parties to collect gifts eventually donated to Howard University and D.C. General Hospitals. Fauntroy also said Dowe had once used his own money to sponsor summer programs in memory of the late City Council member Julius Hobson.

Fauntroy's letter described Dowe as a native Washingtonian and self-employed businessman who had worked in the record industry, the spokesman said.

Dowe used to head an organization called Capital Attractions Inc., on Georgia Avenue, which booked entertainment groups. Dowe said that in 1976 the organization had a grant from the Department of the Interior to produce Summer in the Parks concerts. Dowe said in an interview last night that the company is no longer in existence.

For the last year Dowe said he has been renovating his home at 4843 16th St. NW., and that he is a partner in a second organization called Ramadan Co., which owns real estate. In court yesterday Dowe described himself as "unbelievably in debt."

Yesterday, Judge Robinson agreed to allow Dowe to remain free on bond pending the outcome of his appeal.