HARVARD SQUARE was a contused chessboard this summer; at times the conflict was open, bricks and sticks meeting clubs and tear gas. But more often the conflict was below the surface, a confused struggle which no one understood. The signs of victory and defeat were subtle; the number of policemen in the Square, of boards on shop windows, of panhandlers in Forbes Plaza and newspaper hawkers on the MBTA traffic island, of signs and posters on the boards covering the front of the Cambridge Trust Co., served as an indicator of the flux of forces controlling the Square on each particular day.

The first indication of the coming battle was the influx of "street people" at the beginning of the summer. Like the runaways who came to Boston two years ago, they had heard that Cambridge was where the dope and music were, and they came to cash in. Some estimated the average daily floater population of Cambridge as above 4,000. People working at Project Place estimated by the end of the summer that one out of six street freaks sitting at Forbes Plaza was on heroin.

The influx intensified the uneasy cultural interface in the Square. Panhandlers and Panthers abounded in front of Holyoke Center and on the MBTA island, and, according to Cambridge merchants, the suburban shoppers with the really big money began finding other places to do their shopping.

But, even so, it looked at first as if the City was bending over backwards to be fair, if not friendly. There were, of course, the Sunday afternoon concerts on the Common. And there was also Summerthing's Schaefer Beer Music Festival in Harvard Stadium.

For the first concert, the organizers had gotten a pledge from the police that they would not come into the Stadium unless requested to do so. On June 23, when the Band came to Cambridge to play on the futuristic sound stage erected in the south end zone, the only security forces in the Stadium were hired guards wearing red T-shirts stenciled with peace symbols. At two dollars a throw and no reserved seats, the concerts were not exorbitant; but a lot of people got in free anyway. Half an hour before the concerts began the red ropes indicating authorized seating had lost all meaning as freaks swarmed past them.

The concert itself was euphoric: the Band was in perfect form, and as the evening progressed the crowd surged down into the area in front of the stage, jamming it tight in a mass of wriggling, dancing ecstatic human flesh. The Band played for more than an hour, and at the end of the concert one of them told the crowd, "We're going to tell all our friends in Woodstock that Boston is one of the best places in the world to play music."

BUT if all was good vibes at the Band concert, the Ray Charles show the following Wednesday set the tone for something closer to what the summer would become. Charles' set-piece, big-band presentation did not capture the crowd like the Band's dancing rock. Scuffles broke out in the crowd around the stage as the Ray Charles Orchestra warmed up, escalating into a full-scale fight shortly after Charles came on stage. The blind singer, unaware of the brawl taking place only feet from his piano, continued playing while the crowd, ignoring the music, watched the combatants surging in the pit.

When the fight had been broken up, the concert began again; but the mood was gone, and shortly after the Raelettes had come on stage, a quarrelsome drunk began to heckle Charles from the front of the pit. Visibly annoyed at last, Charles stopped and let the drunk talk while the crowd grew angrier and angrier. Someone in the back yelled "shut up, asshole!", the noise subsided long enough for a brief set, and Charles left hurriedly.

After the concert, the tensions which had smoldered inside the Stadium broke out anew. Gangs of black and white high school students began fighting as the crowd walked up Boylston St., and small groups of teenagers ran along the edges of the crowd, grabbing purses and leaving several women with bloody noses. As the crowd reached the Square, the newsstands closed abruptly, and the purse-snatching and fighting continued around the Square for about twenty minutes until police arrived.

The next day the Record-American and the Herald-Traveler ran big stories headlined "200 Youths Rampage through Harvard Square," and the temperature around the Square began to go up.

But it took a month before the pot began to boil. On Thursday, July 23, leaflets began circulating around the Square urging people to celebrate the anniversary of Fidel Castro's July 25 attack on the Moncada Barracks by holding a "block party" on the Common that Saturday night. Although it did not say so explicitly, the leaflet clearly implied that those who came should be prepared to celebrate violently.

The leaflet became an object of heated debate on Saturday and Sunday. Bread and Roses circulated a counter-leaflet warning that the original leaflet bore the mark of a provocateur: it was male chauvinist, addressing its readers as "Brothers"; it also said "you have to fight," not " we have to fight" as a real movement group would have. In addition, it was unsigned, and contained a rather condescending invitation to Panthers to join in the block party.

Despite the discouragement from Bread and Roses and other radical groups, more than 200 young people-assembled on the Common that Saturday night, milled around confusedly, shouted slogans, and burned an American flag. The group then moved into Square, throwing rocks through windows and looting.

Police from Cambridge, Boston, and the Metropolitan District Commission moved in with nightsticks and tear gas. When the evening was over, five people had been arrested on charges of receiving stolen property, disturbing the peace, and assault and battery. Seven, including two policemen, were treated for injuries.

At this point, the merchants in the Square area, hit by the third sizeable riot since May, began to coalesce into a powerful group in the conflict over the Square. Citing losses of over $50,000 in the latest outbreak alone, they held a meeting the following Monday and decided to ask the City Council for fast action. Since they represented the largest commercial area in the City, they got it.