F. Lee Bailey was seated in the front row yesterday, squeezed in with familiar faces from the John Gotti support group: Peter Gotti, Jack D'Amico and Joseph DeCicco.

New York FBI boss James Fox and supervisor Bruce Mouw, the boss of the FBI's Gambino squad, were seated two rows behind.

And in the row between was Joseph D'Angelo, a young sandy-haired Staten Island man said by a very interested spectator to be "almost an adopted son to Sammy" – Salvatore (Sammy Bull) Gravano, the reason why everyone was packing this particular Brooklyn federal courtroom.

Yesterday was unlike any previous day in the history of the Mafia in New York or the United States – an underboss would testify against his boss, in this case, John Gotti.

Gravano would break omerta, the vow of silence, and his Mafia soul would burn like the picture of the saint that Paul Castellano set afire in Gravano's hand when Castellano "made" him a member of the Gambino crime family in 1976.

Despite the public reasons they uttered, Bailey, the two FBI bosses and nearly all the other spectators were there to see and hear Sammy.

For a time, D'Angelo was squeezed into the first row, on the aisle, where Gravano would be sure to spot him as soon as he took the witness stand.

D'Angelo's position was so obvious that at the request of the prosecutors, Judge I. Leo Glasser ordered D'Angelo out of the first row.

"Your honor," complained U.S. Attorney Andrew Malony, "he's there for one reason, to intimidate and try to make Mr. Gravano perhaps clam up."

Several hours later, after the prosecution called a surprise witness to Castellano's homicide, after some shouting between the judge and the defense lawyers about it, and after lunch, Gravano took the witness stand.

In his two hours on the stand, Gravano did not disappoint his FBI sponsors; D'Angelo (right) did not disappoint his sponsors, whoever they were.

Shortly after Gravano gave his age, 46; the ages of his children, 19 and 16, and his education, eighth grade, D'Angelo, who was wearing a gray-and-white pullover sweater, stood up and slowly made his way down the aisle, and, even more slowly, walked out of the courtroom.

D'Angelo, not much taller than Gravano, had been sitting on his leg before that, but between the complement of suits in the first spectator row and the eight FBI agents seated in front of them, was not doing too well – if intimidation was his game.

Gravano followed him with his eyes as D'Angelo left the courtroom. Moments later, when he returned, Gravano's eyes followed him to his seat. Still, Gravano continued on his mission, to satisfy his current bosses in hopes of possibly getting out of prison, alive.

That would be a marked contrast to the fate of Joseph (Joe Piney) Armone, who was buried yesterday after being waked at the same Brooklyn funeral home where Frank DeCicco, Gotti's first underboss, was laid out when he was blown up and killed in 1986.

Since Christmas 1987 – when Armone was convicted of racketeering and opted for federal prison rather than denounce the Mafia--until last week when he died of natural causes at 74, Armone had been in federal prison.

Along with Gravano, Gotti and DeCicco, Armone was a member of "the fist," the Gambino mobsters Gravano said plotted for more than eight months to kill Castellano before they succeeded a few days before Christmas in 1985.

Armone, like the current underboss sitting next to Gotti, Frank (Frankie Loc) LoCascio, was "made" before the "books were closed" by Mafia bosses in 1957 after a nationwide conclave in upstate Apalachin, N.Y., was raided by the law.

Back then, mobsters, even those like Joe Piney who occasionally dabbled in drugs, were more aware of the Mafia tradition than Gravano ever was, according to his testimony.

Yesterday, after Gravano had testified that he couldn't get "made" because the books were closed from 1957 to 1975, Prosecutor John Gleeson asked: "Did you ever learn a reason for that?"

"No," said Gravano.

Gleeson, who looked somewhat surprised by the response, pressed with two follow up questions, but realized that Gravano had mastered neither books nor Mafia tradition while he was growing up in Bensonhurst, Brooklyn.