This is from Elizabeth Merrill, on ESPN. It is really an interesting look on Belichick, and although lengthy, I suggest you read the whole thing. Here is a snippet:
So now Belichick was asking another favor from his friend, and Ingraham agreed to play the party on one condition: if Belichick agreed to sing one song himself.
“There was a pause on the phone,” Ingraham says.
“What do I have to sing?” Belichick asked. Ingraham said he’d come up with something.
Another pause. “OK,” Belichick finally said. “But it’ll be my song.”
He decided on The Clovers’ 1959 hit “Love Potion No. 9,” rehearsed in a guest house and dabbled with props. Belichick got up on the stage, belted out the 2-minute tune, and swigged from a flask — non-alcoholic, of course — for effect.
His three children were stunned.
“He brought down the whole house,” Ingraham says. “He was so into it. Anyone who thinks this guy is cold, stiff, calculating, I wish they could’ve seen that performance. It’s as human as we can be. He was up there on a stage, entertaining, smiling, not under the influence of anything but ginger ale. It was a fabulous moment that anyone who was there will never forget because this was the guy at his happiest, with his friends and family playing rock ‘n’ roll.”
Ah, but memories are all they have. After the show, Belichick had all video of the performance confiscated.