The K Fed bomb

Word is Federline begged to keep his NYC concert on over the weekend, after only a few fans showed up to watch.

"They were going to cancel this concert, but he begged them to keep it on," a source told Star. "He had to fight with them to keep this concert." Only 300 people showed up at the club that holds 1,500.

Fed was scheduled to start the show at 7pm...but waited several hours hoping that more fans would show up. Didn't happen.

His performance was described as "mercifully short." Britney was a no show...too busy with the divorce details. A witness said he rapped for about half an hour- and he "seemed really confused about how to act on stage. He would pace from one side of the stage to the other, just saying things like, 'Hey' thirty times in a row or 'New York, thank you for coming — buy my CD.' "

The Scoop