They are putting the accent on for the song, same as Americans do. Go and listen to, for example, Wannabe by the Spice Girls. They are singing in an unmistakable english accent. How Bizarre by OMC is in a kiwi accent. And, in the same vein, Americans with really strong accents change their accents for the song to be much milder and more mid-Atlantic.
Amazing how this sub has so many people that are quite happy to chime in on things they don’t know about, or make a guess and share it likes it’s fact. I hope people that ask questions on this sub are aware of that.
This video has the best set of answers from what I have found. [https://www.youtube.com/watch?v=WuK4r3k6iTQ&ab_channel=EatSleepDreamEnglish](https://www.youtube.com/watch?v=WuK4r3k6iTQ&ab_channel=EatSleepDreamEnglish)
The generic American accent tends to be neutral, which happens to align with how songs are sung. Also many accent features like rhythm and speed are overridden when singing rather than speaking.
Youtube video on the subject…
[https://www.youtube.com/watch?v=DQ8RdLtZWlc](https://www.youtube.com/watch?v=DQ8RdLtZWlc)
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