Former Talking Heads frontman David Byrne (left) and Harvard cognitive scientist Steven Pinker (right) kicked off BU’s new arts initiative Monday with a talk focused on Byrne’s new book, “How Music Works.”

Pinker, taking the reins (appropriately, considering his commanding black cowboy boots), introduced theories and then explained why they’re likely wrong, while Byrne, often through nervous laughter, replied with a few alternate (and equally uncertain) hypotheses.

On this they could agree: Music is related to the natural rhythms in daily activity and speech, and sounds have the potential to carry inherent meaning. Byrne pointed to a study in which people across cultures were asked to name two shapes — a spiky star figure and a rounded blob — either “Kiki” or “Bouba.” He said 95 percent to 98 percent of respondents agreed that Kiki was the jagged one and Bouba was the curved one.

Byrne, who’d performed with collaborator St. Vincent at the Orpheum on Sunday, also revealed that when writing lyrics, he frequently improvises nonsense sounds over the melody first. (We’ve long suspected this was the case.)

“There’s a meaning, preverbal or nontextual, that’s being articulated with those sounds that I have to adhere to,” said Byrne. “That’s where some of the meaning is, some of the emotional meaning.”

During an entertaining Q&A session that followed, one woman in the crowd took issue with Pinker’s argument that solitary music appreciation disproves the idea that music was created for communal purposes. She pointed out that individuals enjoy certain, um, reproductive activities by themselves, even though it takes two people to achieve the biological goal. (Pinker conceded that she had “a legitimate counter-counter-counter argument.”)

With a shout-out to David Rothenberg’s discussion of bird songs in the book “Survival of the Beautiful,” Byrne closed the night by appealing for a common sense reason for music: “There’s a certain pleasure just in doing it.”