Brett and Rennie Sparks

but I'm not sure that their being married has anything to do with it. Then again, maybe it does - I guess there may be a distinction to be made between creative individuals who marry and make music or make music and marry and those where one of the couple is included when perhaps their contribution is of a more negligible value.

Chris Frantz/Tina Weymouth
John & Christine McVie (before...y'know)
Suzi Quatro/Len (not Ken) Tuckey
Avril Lavigne and Him Out Of Blink 182
*update* Toyah Willcox & Robert Fripp

Not 'Rock':

Martin Carthy and Norma Waterson
Stacey Kent & Jim Tomlinson

Kind of in the middle:

Elvis Costello & Diana Krall

Mick & Keith, Mozz & Johnny, Neil & Chris...

Out of Aimee Mann and Michael Penn and Stacy Earle and Mark Stuart, I'd say the Ladies have the edge over the Gentlemen in terms of talent (not by a huge amount, but still).

There's also John and Beverley Martin, though I've never heard anything by Bev.

would seem to fit your definition ... at least for a while

Gerry Goffin & Carole King. Jeff Barry & Ellie Greenwich. Nick Ashford & Valerie Simpson. Cecil & Linda . . .

- the Posh & Becks of their day, in a good way (actually is there a good way?). Anyway, I read once - perhaps in my trusty NME Illustrated Encyclopeadia of Rock - that they were once the highest earning couple in showbiz.

The First Couple of Country Music.

... are both rather groovy.
As were John Coltrane and Alice Coltrane.

Worth seeing - if only for the lovely Nina...

Anni-Frid, Björn, Benny & Agnetha. bit of twofor.

Mark Olsen and Victoria Williams (Ex)

?

Amy Rigby & Wreckless Eric

Susan Tedeschi and Derek Trucks
Amy Rigby and Wreckless Eric
Kathleen Edwards and Colin Cripps
Tom Waits and Kathleen Brennan
Gillian Welch and David Rawlings (though I'm not exactly sure (is anyone?) if they're a couple or not).

Everything But The Girl. Not sure they´re married, but they met in the early eighties and have three kids.

(& Willie Nelson)

All this time, and no mention of Captain and Tennille?

Although now divorced.

then Harry n'Stein ?

Elvis Costello and Cait O'Riordan, too

A rare case where the female takes the musical lead in the partnership?

(Were they married?)

knew the song, never saw the video. Would be easy making sweet music staring across at her that's for sure.

before it went tits up

Sandy Denny and Trevor Lucas

Dave A Stewart and Barbara Gaskill

From Planet Jazz

Carla Bley and Steve Swallow

Stormbringer and Road to Ruin, pretty good LPs.

and Colin Moulding, apparently (see thread elsewhere)

from da Youth.
Gillian Gilbert and Stephen Morris from New Order

kicked off this thread!!

Firstly with Rodney Crowell and latterly with John Leventhal.
Emmylou Harris and Bruce? Ahern.

...were A.P. and Sara Carter. Maybe the original first couple of 'popular' music?

any musicians not married? :-)

Amadou and Mariam.

In jazz, I think a fair few of bandleaders married the singer/got their wife to sing.

Artie Shaw married about twenty times, and I can't remember them all, but there must have been a singer in there somewhere.

Tabitha Tindale and Vincent Cafiso are married.

Genius at work indeed.

Nick Lowe was married to Carlene Carter.
Carlene later got involved with one of Tom Petty's Heartbreakers. Which he did after a fashion, getting her into a heavy drug habit, dying on her and then she got arrested on drugs charges. Of course she's cleaned up now.
Loudon Wainwright and Kate McGarrigle.
Did Paul Kantner and Grace Slick ever get married or did they just share a bed and kids?
These days you could say Neil and Pegi Young as she's been singing backing vocals for him for quite a few years now.
Chuck Prophet and Stephanie Finch.
Sarah McLachlan and Ashwin Sood - who someone posted in another thread have split.
Keith and Donna Godchaux of the Dead.

Steve Earle and the current Mrs Earle. Number 8 I think? The lovely Allison Moorer

Guy and Suzanna Clark. She does backing vocals on some of his records.

Boy George and Jon Moss
(well they were as good as)

Betty Davis.

Cliff Richard - had the chance to shag Sue Barker but bottled it - allegedly!!

A new entry would be Neil Finn as apparently his missus sings on the new 7 Worlds collide cd.

Might be stretching the definition of making the best music together but how about Mark E Smith and a series of significant others who have added considerably to the music of The Fall. Brix was the most high profile and was in the pretty good Adult Net, and she also went onto to marry(?) Nigel Kennedy

Surprised to be the first to mention these two.

singers
also
John and Johanna Hall (ex) - Writers of 'Miss Grace', John in Orleans etc.
and country duo, the superb Buddy & Julie Miller
Oh, and the Woodies

edited for omission

Budgie

Not a bad list of songs

California Soul
Let's Go Get Stoned
Ain't No Mountain High Enough
Your Precious Love
Ain't Nothing Like the Real Thing
You're All I Need to Get By
Remember Me
I'm Every Woman

Now if she joined the band as a second lead singer we could be onto a winner!

and Lee?

Sylvian/Ingrid Chavez.
Toyah/Whatsisname.

couple at the heart of them: Insides, Laika, Prolapse, The Field Mice, Sleeper and a few more mentioned above and below.

The following are, or were, married. I'm sorry if any repetitions slipped through:

John and Alice Coltrane
Joao and Astrid Gilberto
Tony Hatch and Jackie Trent

Boss Hog: Jon Spencer and Christina Martinez
Royal Trux: Neil Hagerty and Jennifer Herrema - like White Stripes, they divorced and formed a band
Luna: Dean Wareham and Britta Phillips - Wareham was already married, recruited Phillips to the band, one thing followed another and then he wrote a book about it

Stereolab: Tim Gane and Laetita Sadier - divorced but still recording together
Le Tigre: Kathleen Hanna and Johanna Fateman - are they a couple? It's been a while since I could interpret Riot Grrl.

Married: Rosie Cuckston (Pram) and Tom Fenn (Tele:funken)
Divorced: Paul Morley (Art of Noise) and Claudia Brucken (Propaganda)

Mark E. Smith: an early girlfriend, Kay Carroll, was The Fall's first manager; Brix Smith, his first wife, made The Fall more accessible; Safron Pryor, his second wife, worked at Cog Sinister; Smith was arrested for assaulting Julia Nagle, band member and girlfriend, and I put my Fall records away for seven years; Smith's current wife is Elena Poulon, on keyboards. I've seen four different spellings of her first name.

Lots of people marry other people in the same business.

Esther and Abi Ofarim?