how come when british singers sing, they seem to put on an "american" accent?

As someone above correctly noted, rock & roll was initially an American invention, so when the Brits went into rock, the adopted the (American) singing mannerisms of the artists they were imitating.

Not that this goes both ways: a lot of American bands adopted the (English) singing mannerisms of the British new wave bands of the 80's, and some American singers (like Billy Joe of Green Day) openly adopt English accents in singing as part of an homage to the artists who influenced them (in the case of Billy Joe, think Joe Strummer of The Clash.)

Before the "British invasion" -- the rise of the Beatles and other English rock groups -- rock was closely associated with the United States and with American accents. My guess is that many non-American singers mimicked some of the sounds and expressions that they heard their favorite American singers using (just as within the United States white blues singers mimicked black singers). Singing itself might have accents but I believe that there was probably some conscious imitation too.

Do you think the Beatles copied American accents, or were they just popular because they were the Beatles? (I think I know the answer to that one.)

Rock and Roll is a language for the purpose of being sung to music. It also has its accent, which is American because that's where Rock and Roll came from.

It's fair to say all singers from around the world adopt this accent much the same as actors adopt an English accent when performing Shakespeare.

Some do like Elton John and Mick Jagger. Greenday and The Killers attempt to sing with English accents. You ought to compliment ladies like Sophie Ellis Bextor for making a song in a staunch English accessory, it does not paintings at all times although, the equal approach that Shakespeare sounds ludicrous with an American accessory. Remember there are plenty of variants inside the English accessory, now not regularly detectable to the untrained ear as Angela D says beneath (although a few English artists do certainly sing with American accents), you can also feel it is American while it honestly is not. EDIT Pavel C presents the necessary "fool reaction" wanted for each exciting query. Remember whose language it's Pavel C, without reference to the sound (might as good talk to him at his possess degree).

Yeah, there was this comedian who joked about this by speaking in a British accent to announce the song and then singing in a nice Bronx, NY accent in the song. Hilarious. I have no idea why I can't understand UK singers until they sing and their British accent magically disappears.

As Bing Crosby said : "That's where the money is. "

Ask yourself which would sell more records : an American Accent or an Australian / British accent ?

The American market is always the one to aim for. The money to be made there is huge and success in the US often flows through to the rest of the world.

Usually when people sing, they just sing. You don't hear an accent. They probably think Americans sing with an English accent.

Because we all usually sing with longer vowels, dropping r's, things like that.

Yeh, I know..especially the country performers...Kasey Chambers is a huge one that if you didnt know better would think she was twanging away at Nashville for a living.

I think it is purely a marketing thing...they figure if they sound American, then the American public will take on their music more readily...and to tell you the truth, they arent that far wrong. If you look at those who make it big, and those who dont in American music charts, it is usually those who have an American twang to their music.

That's True... When singers from other countries sing in English, you can't tell where they originally from. When they start talking, then they have the accent somehow. I don't get it.

e doesnt, I LOVE THE WAY HE SINGS, WITH his accent!

Ok, it won't le me post the link, but look up Across the universe "Ive just seen a face" or "revolution" or "strawberry feilds forever" or any song e sings on youtube