Well, after consideraton of the excellent suggestions posted here, combined with my own collection and resources, I've put together a pretty nice playlist of duets of various types. Included are true duets (alternate verses, simultaneous singing, etc) and some cheating -- primary male or female, with signficant harmony from the alternate sex). It's fun. Selected content follows. I thought of posting an iTunes mix but gave up after a bit because a number of the cuts weren't available there (and hence couldn't be listed on the mix). Most were, though,so if you want me to do this with a view to buying the tracks, let me know.

The genres range from roots/country/folk through 50s jazz and modern cabaret style.

If you`d like an MP3 CD of these, let me know -- if you promise to think about buying the tracks. Write to me personally.

R.

Alison Krauss, James Taylor: How's the World Treating You
Ane Brun, Ron Sexsmith: Song No. 6 (I love this song)
Lyle Lovett, Shawn Colvin: Faded Love (Asleep at the Wheel, Ride With Bob)
Bruce Cockburn, Margo Timmins: Blueberry Hill (I love this song, too)
Gasoline and Matches: Buddy and Julie Miller
In a Town This Size: Camille and Stuie (Aussie duet, Kieran Kane song)
Sweet Thing: Carolyn Mark, Corb Lund
I'm So Lonesome I Could Cry: Carolyn Mark, Luke Doucet
Bottom Dollar: Christopher Rees, Victoria Williams (I love Victoria Williams)
Voodoo Child (Slight Return): Angelique Kidgo and varius (not really a duet, but male/female voices involved)
The Indie Queens Are Waiting: Dan Mangan and Veda Hille (where has Veda Hille been all my life?)
Cold and Lonely Night: Diana Braithwaite and Chris Whiteley (new blues in the Chicago style)
The Drifter: Diana Braithwaite and Chris Whiteley (ditto)
Makin' Whoopee: Dr. John and Rickie Lee Jones (won a Grammy for this one)
Let's Call the Whole Thing Off: Ella Fitzgerald and Louis Armstrong (how classic can you get!)
Love Is Here To Stay: Ella Fitzgerald and Louis Armstorng (ditto)
Billy 4: Gretchen Peters and Tom Russell
Baby, It`s Cold Outside: Holly Cole and Ed Robertson (of Barenaked Ladies) - excellent jazz treatment
Four Strong Winds: Ian and Sylvia
You Were On My Mind: Ian and Sylvia
Make Èm Wait: Ike and Tina Turner (not really a duet, but Ike makes an occasional baritone statement, from the Phil Spector produced River Deep LP)
Joan of Arc: Jennifer Warnes and Leonard Cohen, doing Cohen`s classic song
Other Side of Life: Jenny Whiteley and Jim Byrnes
In A Town This Size: John Prine and Dolores Keane (interesting contrast to the other version of this Kieran Kane song on the list)
What a Wonderful World: k.d. lang; Tony Bennett (kd may have moved away from weirdo country, but is still the best)
People Get Ready: Ladysmith Black Mambazo, Phoebe Snow (truly excellent)
Ain`t No Sunshine: Ladysmith Black Mambazoo, Des`ree (I heard this on the radio and had to have it)
Dimming of the Day: Richard and Linda Thompson (absolutely classic, best folk duet ever in my opinion)
Roly Poly: The Little Willies (incl. Norah Jones) - I first heard this song in a version by The Dixie Chicks, but I like this better)
Portland Oregon: Jack White, Loretta Lynn
North Dakota: Lyle Lovett, Ricky Lee Jones
Hold On: Mae Moore, Lester Quitzau (I love this version of the Tom Waits song)
Java Jive: Manhattan Transfer (not a duet, but two voices in each of male and female persuasions)
Save the Last Dance for Me: Manhattan Transfer (and Ike and Tina classic, done right by MT)
I Got To Move: Maria Muldaur and Alvin Youngblood Hart (from Maria`s Richland Woman Blues, just truly excellent)
Soul of a Man: Maria Mulduar, Taj Mahal (see above)
The Crane Wife 3: Marianne Faithful, Nick Cave (cabaret style, great)
Sing Me Back Home: Marianne Faithful, Keith Richards (40 years on, they still sign well together)
All the Roadrunning: Mark Knopfler, Emmyulou Harris
Give my Heart to You: Mark Olson and the Creekdippers (incl Victoria Williams)
Never Any Good: Martin Simpson, Kate Rusby (a great, great song, with Kate Rusby singing harmony)
This Old Guitar: Neil Young, Emmylous Harris
Love Will Tear Us Apart: Oysterband -- June Tabor and John Jones (June is the best English female folk singer in my opinion)
True Love Leaves No Traces: Patricia O`Callaghan, Stephen Page (cabaret style, with Page from Barenaked Ladies)
Duet: Polymaths (I don`t know anything aobut them, but from Regina where I lived for a while, and quite neat)
Grey Dusk of Eve (Portobello): Rankin Family, excellent Canadian Atlantic Provinces group, now sadly disbanded
Nothing Halfway: Rick Fines and Suzie Vinnick
Don`t Let Your Dreams Drift Away: Rick Fines and Suzie Vinnick
Gone Gone Gone: Robert Plant and Alison Krauss (jsut because it`s commercial doesn`t mean it`s not great)
Stick With Me Baby: Robert Plant and Alison Krauss (see above)
My Body Moves: Tannis Slimmon, David Francey (Tannis did a house concert at my place, but this song deserves it`s position independently)
My Heart Echoes: Teddy Thompson, Iris Dement
Crying: k.d. lang, Roy Orbison (hard to find, on a film soundtrack, but essential, wonderful)
Sin City: Emmylou Harris and someone else
Harmony: Audrey Auld and Kieran Kane
Road: Robin Holcomb and Veda Hille (I`ve always been a Robin Holcomb fan, but, again, where has Veda Hille been all my life!)
Keep It Clean: Judy Larson and Bill Hinckley
Why Baby Why: Deborah Pierce and Kevin Welch
When We Sing Together: Victoria Williams and others
Humming Bird: Victoria Williams and others
Heaven Help Us All: Wiliam Galison and Madeleine Peyroux
Mango: Bruce Cockburn and Margo Timmins
The Smokey Life: Patricia O`Callaghan and Stephen Page
Take a Message to Mary: Teddy Thompson and Linda Thompson

Best,

Ron