Someone broadcast on President Trump's YouTube channel may have just learned a valuable lesson in the importance of the mute button.

Trump lawyer Rudy Giuliani on Thursday held a bizarre hour-and-a-half press conference leveling baseless allegations of widespread voter fraud in the 2020 election, and it was streamed on Trump's verified YouTube channel.

But those who tuned in could at one point hear unidentified people, who apparently didn't realize their audio was being broadcast, mocking Giuliani by joking about "Rudy's hair dye dripping down his face." The former New York City mayor could be seen sweating during much of the event. The person who made that comment was also heard asking, "Can they hear us on the stream? I guess not." In fact, they could.

Among other strange highlights from the affair was the revelation that Giuliani is apparently getting legal advice from Joe Pesci movie characters, as at one point, he quoted a scene from the 1992 comedy My Cousin Vinny to make a point about not being able to see things from far away, describing it as one of his favorite films and offering a not exactly spot-on impression of Pesci.

"Did you all watch My Cousin Vinny?" Giuliani asked reporters. "You know the movie? It's one of my favorite law movies because he comes from Brooklyn."

The Trump YouTube channel apparently removed the video of the press conference including the audio of Giuliani getting mocked, for, well, obvious reasons. Brendan Morrow

President Biden was sworn in as the United States' 46th commander-in-chief Wednesday, succeeding former President Donald Trump.

Chief Justice John Roberts administered the oath of office to Biden with his wife, Dr. Jill Biden, at his side holding the family bible.

Sen. Amy Klobuchar (D-Minn.), one of the inaugural committee chairs, then introduced Biden by his new title for the first time, and he launched into his initial speech on the job. Tim O'Donnell

Lady Gaga just brought the house down at President Biden's inauguration.

Gaga, using a gold microphone, sang the national anthem at the start of Biden's inauguration ceremony, the first of numerous performances that were set to take place on Wednesday; minutes later, Jennifer Lopez also won praise for her performance.

Gaga has a history with the new president, having previously worked with him on a campaign against sexual assault and performing at a rally for him during the 2020 election. In a Twitter thread earlier in the day, Gaga called it an "honor" to be performing the national anthem.

"I will sing during a ceremony, a transition, a moment of change — between POTUS 45 and 46," Gaga wrote. "For me, this has great meaning. My intention is to acknowledge our past, be healing for our present, and passionate for a future where we work together lovingly. I will sing to the hearts of all people who live on this land." Watch Gaga's performance below. Brendan Morrow

Kamala Harris took the oath of office on Wednesday, making history as the first woman and first woman of color to break the glass ceiling of the executive branch.

Harris also makes history as the nation's first African-American and first South Asian vice president of the United States. Supreme Court Justice Sonia Sotomayor administered the oath. Watch the moment below. Jeva Lange

Vice President Mike Pence has arrived at President-elect Joe Biden's inauguration— while President Trump, at almost the same time, landed in Florida.

Pence was introduced at Biden's inauguration on Wednesday alongside second lady Karen Pence, and they received "hearty, bipartisan applause," CNN's Jeremy Diamond writes. The vice president's arrival was more notable than usual considering Trump refused to attend the ceremony, leaving Washington, D.C., beforehand despite the tradition of presidents being in attendance for their successor's swearing-in.

Trump had departed on Air Force One for Florida earlier after delivering farewell remarks, and the plane landed within minutes of Pence being introduced.

Among those who were previously introduced at the inauguration include former Secretary of State Hillary Clinton, and according to CNN's Kaitlan Collins, Clinton went "out of her way to greet" Pence, and "they exchanged a few words." Despite his refusal to attend the inauguration, Trump left a note in the White House for Biden, as is tradition, and The New York Times' Maggie Haberman reports Pence also left a note for his successor, Vice President-elect Kamala Harris. Brendan Morrow

It's a little known fact that the presidential inauguration actually doubles as a fashion show of preppy winter 'fits, and President-elect Joe Biden's was no different. But the winner of the Capitol steps on Wednesday wasn't Michelle Obama, in her plum Sergio Hudson, or Vice President-elect Kamala Harris' step-daughter, Ella Emhoff, in her embellished coat, or Jill Biden, in her custom blue Markarian.

No, it was the grumpy chic outfit of Vermont Sen. Bernie Sanders:

Sanders, naturally, wears mittens made by a teacher from Essex Junction, Vermont, and knit from "repurposed wool sweaters and lined with fleece made from recycled plastic bottles," BuzzFeed News' Ruby Cramer reports. Jeva Lange

President Trump departed Washington, D.C., before President-elect Joe Biden's inauguration ceremony, but three of the other four living presidents and first ladies have gathered on stage to support their latest successor. Bill and Hillary Clinton, George W. and Laura Bush, and Barack and Michelle Obama were all introduced ahead of the ceremony.

It's customary for former presidents to attend the inauguration — the Clintons, Bushes, and Obamas were all at Trump's ceremony in 2017 — though Biden's event comes amid a pandemic and security concerns following the Jan. 6 Capitol siege. Still, they were all on board.

Former President Jimmy Carter, meanwhile, decided not to attend, marking the first time he's missed a ceremony since he was sworn in in 1977. Of course, it's quite safe to assume the 96-year-old Carter is not snubbing Biden, but rather staying home for health and safety reasons, as he has through much of the pandemic, per ABC News. Tim O'Donnell