Meghan Trainor appeared on “Carpool Karaoke” on Thursday night, and the host James Corden had a special surprise for the 26-year-old pop star an unexpected appearance from Dr. Phil.

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During the segment, Trainor and Corden sang along to several of her songs, include “All About That Bass” and “Like I’m Gonna Lose You,” and also talked about her career. Trainor, who became singer-songwriter when she was just fifteen years old, told Corden that she almost did not become a pop star. “A lot of people were like, ‘Wow, you should be a songwriter,’ and I was like, ‘I am a songwriter.’ But they were like, ‘You should do that professionally.'” Trainor also told Corden that before she became well-known, people would tell her to focus on songwriting instead of pursuing singing. When asked why people doubted her stage presence, Trainor said that she, “looked as insecure as she was.”

Trainor discussed her surprising obsession towards television host Dr. Phil. “I worship Dr. Phil. I went to his show the other day and I couldn’t stop crying,” said the pop star. Corden initially thought that she appeared as a guest on the show, but Trainor clarified, saying that she was in the audience after her brother got her tickets for her birthday. “It was the greatest day of my whole life,” said Trainor, who watches Dr. Phil every day and claims to have seen every episode more than once. Soon after, Dr. Phil entered the car, prompting a joyful shriek from Trainor. “I’m so excited, your teeth look so good,” Trainor said to the 69-year-old psychologist.

Trainor’s new album Treat Myself was partially inspired by her panic disorder, revealed the singer. Dr. Phil then thanked the singer for talking about mental health to such a wide audience. “Millions of people will be saying, ‘If she can talk about it, I can talk about it.'” Corden and Dr. Phil then sang “All About That Bass,” which excited Trainor.

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