Beyonce endorsed Kamala Harris at a Houston rally on a night that also saw Donald Trump arrive three hours late to an event as he was recording a podcast with Joe Rogan.
Many of the Republican presidential candidate’s supporters left the Michigan event early on Friday as the former president was interviewed for the Spotify broadcast.
Mr Trump is said to be aggressively courting the 14.5 million strong, mostly male, audience of the Joe Rogan Experience - and told supporters who had been waiting in the 10C cold that he hoped they “wouldn’t mind too much”.
The crowd erupted into cheers as video screens showed Mr Trump's plane arriving and then him walking off his plane and down the steps.
"I am so sorry," he said. "We got so tied up, and I figured you wouldn't mind too much because we're trying to win."
Throughout the lengthy conversation with Rogan, Mr Trump told familiar stories but occasionally dropped new colour and nuance.
Rogan pressed Mr Trump on whether he's "completely committed" to bringing vaccine skeptic Robert F Kennedy Jr into his administration.
"Oh, I completely am," Mr Trump responded, but added he and Mr Kennedy disagree on environmental policies. He said he'll tell Mr Kennedy to "focus on health, do whatever you want."
Beyonce, meanwhile, told the Democratic nominee's biggest crowd ever that it was "time to sing a new song" after Ms Harris warned that Mr Trump was dead set on further eroding women's rights.
The singer, making a rare political appearance, told the crowd: "For all the men and women in this room, and watching around the country, we need you.
"I'm here as a mother, a mother who cares deeply about the world my children and all of our children live in.
“A world where we have freedom to control our bodies, a world where we're not divided."
The rally was set in reliably Republican Texas, to highlight the growing medical fallout from the state's strict abortion ban, but the message was intended to register in the political battleground states, where Ms Harris is hoping that the aftereffects from the fall of Roe v. Wade will spur voters to turn out to support her quest for the presidency.
The US goes to the polls on November 5.
