Have you ever wondered why British singers don't "sound British" when they sing?
As in, singers who have heavy accents in interviews just sound vaguely American in their songs.
The simple answer is that singing prevents vocalists from stressing syllables, according to Josef Fioretta, a linguistics professor at Hofstra University.
When syllables aren't emphasized like they are in a normal speaking pattern, they become neutralized, Fioretta explained.
It could also be that some performers with foreign accents deliberately choose to sound American to reach an American audience.
For example, contrast Keith Urban's Australian accent, which comes across in his speaking voice...
...with the Southern twang he sings with in his music.
But sometimes you can hear singers' foreign accents, like in a lot of songs by The Clash.
For another example, Lily Allen's accent is more apparent in the more "spoken" verses of "Smile" than in the choruses.
But this explains why, as an American, you could potentially never know a singer had a foreign accent until you heard them speak.