I know of two bands where every member was capable of writing the music and handling the vocals. The two bands are Kiss and The Beatles. Can you think of any others?

Do you count duos in the mix? If so, I think The Pet Shop Boys qualify. Wait, does it have to be the lead vocals or do backing vocals also count? If backing vocals count too, then The Who qualifies. I would add Guns N' Roses, but while I know that Slash can sing, he doesn't like to, and I don't recall him singing on an album.

The Travelling Wilburys. I don't know if super-groups like that count, but they meet the your qualifications. Other than them, I can't think of any either.

Queen. John Deacon didn't sing often as he was a fairly withdrawn person, but he did provide backing vocals when live.

All I know about Kiss is that it was a rock band with members who wore unique costumes and make-up. The Beatles is probably the best band of all time; I even got a book to try and understand what Beatlemania was all about. Why do great bands break up after a while?

Ben Folds Five. Ben Folds writes most of their music, but there have been some group collaborations and all three obtained songwriting credit for those. All three guys sing.

Why do great bands break up after a while?

Their egos get too big.

@Gareth The Great, does Chris Lowe really ever sing?

 

Time to add some boy bands to the mix with One Direction and The Jackson 5. One Direction wrote a few of their hit singles and they all sing. The Jackson 5 had many hits that were written by Motown pros with an ear for commerciality , but the brothers wrote some of their own music that made it onto their albums, and they all sang as well.

Their egos get too big.

I agree; there's nothing as hard to tame as an inflated ego. All the same, I am sure that there are a few bands whose members broke away, then went on to have successful solo careers.

@Gareth The Great, does Chris Lowe really ever sing?

Sorry it's taken me so long to see this. Does Chris Lowe sing? I have no idea if he can or can't. He does perform spoken word vocals and those meet the OP's criteria in my opinion.

 

@Gareth The Great, you're right, I just forgot about that one. Thanks for sharing the clip. I don't think I've ever seen him play live before. I enjoyed it!