Under the 110-foot soft gray Indiana limestone arches of the Cathedral of St. John the Divine, about 1,000 of John Belushi's friends and family mourned today as they thought he would have had it, if he were in town instead of away.

As many jokes as prayers filled the huge cathedral, and more laughter than organ music rose through the light that filtered down from the stained glass windows.

"I can't help but think," Belushi's younger brother Jim said as he looked out into the massive Gothic cathedral, "John would have loved to play this room."

He couldn't, so his brother and his friend, comedian Dan Aykroyd, who called Belushi "America's Guest," played it for him. "I still think," said Jim Belushi, wearing a disheveled uniform of a sports jacket and yanked tie, "I'm going to see him roll down this aisle doing somersaults. I think he still thinks he really did those somersaults in the church in 'The Blues Brothers.'

"Older brothers are sort of like fathers," he said, "and his approval was like the sunshine. You couldn't do too much for John except get him an ashtray. But everybody else got things from him." He said his brother once took him to a bathhouse. "He dragged me in and threw me into a hot, hot room. 'John,' I said, 'I think I'm going to pass out.' So he grabbed me and put me in a cold tub. And then I went into a shower, and he came over with a bottle of shampoo and he washed my hair. Here I was, 25 years old, and my brother was washing my hair. John never said, 'Hey, Jim, I love you,' but that day he did. Not in words. But he washed my hair."

The cathedral at 112th Street and Amsterdam Avenue in Manhattan had colleagues from the old "Saturday Night Live"--including Bill Murray, Michael O'Donoghue, Laraine Newman, as well as an entire row of the members of the show's current performers, and friends Paul Simon, Hunter Thompson, Carly Simon. When Jim Belushi and Dan Aykroyd did their stand-up eulogies the mourners laughed hard, and when they were through laughing, many people cried and held on to each other before they began laughing once more.

"I don't know if I have anything else to say," Jim Belushi said near the end of his talk. "I feel like falling on the floor. Whenever John didn't have anything else to say, he'd just fall on the ground."

Jim Belushi spoke of the closeness of the family, his parents, his grandmother, his other brother, his friends, his widow, Judith Jacklin. "John had something to give to everyone," he said. "He even had some thing to give to reporters, who are still getting something, it seems," he said.

Jacklin, in an interview with the Chicago Sun-Times today, responded to the Los Angeles County coroner's report that Belushi died of an overdose of cocaine and heroin. She talked about the circumstances of his death and told the reporter, "He wasn't a junkie. He had trouble, but he wasn't a junkie. He didn't like needles, he didn't even like taking a blood test."

After more prayer and a saxophone-dominated song, "For a Dancer," by three musicians, Dan Aykroyd in a dark suit and big black Elvis Costello-like horn-rimmed glasses strode a long way up the center aisle of the cathedral carrying a blue knapsack. "I was as star-struck by him as any of the 11-year-olds in the audience," he said. "He was a master. He was a member of the most liberal society in the world, and he took advantage of it. For something to be fun for John there had to be an illicit thrill to it."

The audience laughed. "He was not an innocent person--I think we all know that. He was a good person though, and he gave to others. What we are talking about is a good man, and," Aykroyd lowered his voice and brought his mouth very close to the microphone, "a bad boy."

He stopped for a moment and looked around. "All the doors in the continent were open to him. He would walk into the homes of complete strangers--I watched it happen and I heard a number of stories about it--and go into the kitchen, open the refrigerator, make a snack, turn on the TV and go to sleep on the couch, while the family at home watched in amazement and delight. I once told him and he liked it, that he was America's Guest.

"Johnny," Aykroyd said, "you never wore out your welcome."

Speaking evenly and slowly, Aykroyd nevertheless looked pasty and dazed. He told the mourners that Belushi "hated being a bee. The first time we sang together he was dressed as a bee, but he liked being that bee because in that song he sang as the King Bee.

"Last summer he was going to go to Paris, and I said, 'Why, what do you want to go over there for, with all those tourists and the crowds? Come up to Martha's Vineyard.' If I did nothing else for him, I'm pleased I talked him into staying on the Vineyard because he had a great time. One day we were out driving, and I pulled out a tape of the Ventures playing a song and we both loved it. And we agreed that whichever of us died first the other would play it at the funeral and force everyone to listen to it, loud enough so that nobody could really enjoy it."

Aykroyd opened his blue knapsack, and pulled out a tinny tape recorder and held it next to the microphone. "And so, here's a little instrumental by the Ventures, 'The 2,000-Pound Bee.' " The Ventures' guitars in their bee patterns filled the Cathedral of St. John the Divine, reached nooks and naves that probably hadn't been checked out before.

Hundreds of people sat, stunned at first, and then began to rock and laugh. Their laughter took over, the real thing, the authentic laugh of new comedy that ambushes an audience, that Aykroyd and Belushi made raw and mean and yet somehow affectionate. There wasn't a person in the cathedral who didn't understand the joke, and it was the tribute to John Belushi that there probably wouldn't have been a person under 35 in America who wouldn't have.

When the great-bad music and the laughter finally stopped, Aykroyd looked out and said, "So there, Johnny, and you can be sure that I'll have my antennae out for the paranatural and the spiritual, and believe me, if there's any contact with him," he looked out to the audience, "I'll let you know."

Applause rose through the air, 110 feet to the height of the arches, and higher. And after the minister told the story about how John Belushi had draped a pink electric bass guitar around the minister's neck and told him to play, and after the Belushis and the comedians and the musicians and the New York hipsters and the technicians who had wired the old show sang "Blest Be the Ties That Bind," the mourners stood up, hugged each other here and there and walked out through a side door onto Amsterdam Avenue where there was no laughter, but only silence, a hint of spring and rented limousines.