Watch Elon Musk pronounce his baby's name, which he says Grimes mostly picked out

• Ever since Elon Musk announced his new baby's name — X Æ A-12 Musk — on Instagram earlier this week, the world has been wondering how to pronounce it.
• Musk cleared up the mystery on Thursday when he pronounced it out loud on the "Joe Rogan Experience" podcast. Musk said the name is pronounced "X Ash Archangel."
• Musk's pronunciation is different from his partner, Grimes': In an Instagram comment this week, Grimes said the name is pronounced X A.I., or, phonetically, "ecks aye eye."
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Ever since Elon Musk revealed his new baby's name on Monday, the world has been wondering: How do you pronounce X Æ A-12?

Musk's partner, the musician Grimes, explained more about the baby's name in a tweet on Tuesday, clarifying that X stands for "the unknown variable," Æ is her "elven spelling" of AI, and A-12 stands for Archangel, the internal codename of a US spy plane.

In an Instagram comment, Grimes further explained that she pronounces the name X A.I., or, phonetically, "ecks aye eye."

But Musk has a different pronunciation, which he said out loud publicly for the first time on the "Joe Rogan Experience" podcast, which published Thursday. When Rogan asked how to pronounce the name, Musk said it's "X Ash Archangel."

"It's just X, the letter X. And then the Æ is, like, pronounced 'ash,'" Musk told Rogan. "And then A-12 is my contribution ... Archangel-12, the precursor to the SR-71, coolest plane ever."

Musk said Grimes was the one who came up with the name. "She's great at names," Musk said.

You can watch Musk pronounce the name below, starting at the 0:34 mark:

One Twitter user was among the first to guess the name correctly. On Monday, a user who goes by the name "Viv" tweeted that they interpreted the name as "X Ash Archangel," and Musk liked the tweet, leading people to believe it was the right guess.