The chorus had long since quieted. The baritone bleatings regarding the acquisition of Jeff Green, complete with the “We miss Perk” interlude from the backup singers, had faded to barely audible. Maybe it was when Green dropped 31 points in Phoenix or when he threw in 43 against Miami or shot 51 percent during his last 18 games. We can’t be certain. But we do know that no negative sounds could be heard in the first half last Saturday when Green was outplaying the Eastern Conference Player of the Month, scoring 20 points on 10 shots to Carmelo Anthony’s 19 points on 15 shots, as the Celtics built a four-point lead on the Knicks. Folks watching were saying things like, “Hmmmm,” and, “Damn.” You know, deep stuff. Where there had been derision for the trade and more rip-ture regarding the four-year, $36 million free agent deal he signed last summer to stay, there was respect — albeit with a raised eyebrow. But Jeff Green doesn’t need anyone else to rain cold water on his parade from aortic aneurysm surgery to 20 points in the first half of a playoff game. The man who once again displayed the huge vertical scar on his chest as he put on his practice jersey yesterday offered the most cutting remark. “They won,” Green said of the Knicks, as if to cut off the pleasantries regarding his performance. Indeed, New York came back to take the game, 85-78. Anthony went on to score 36 points. Green added just six to his total, making 1-of-5 shots after the break. However, because of the way the Celts collapsed so hideously as a team, no one was pinning this on him.