This was brought up by DonFan in another thread... why hasn't Glenn ever done a duet with a lady? We have evidence that his voice sounds great with a woman's!
These are the songs he's sung backup on with women:
Linda Ronstadt - Rescue Me (Live 1971) - he goes back and forth with her at the end
Linda Ronstadt - I Ain't Always Been Faithful (1971)
Joni Mitchell - Off Night Backstreet (1977) - pretty much just on the word "backstreet" lol - not worth checking out if you don't like Joni
Karla Bonoff - If He's Ever Near (1982) - especially about 2:00 min and onwards - PS, I LOVE this song!
Laura Creamer - Love Letter (2002) - probably the closest we'll get to a Glenn duet, on the choruses at least (The song is on her MySpace Player)
On this one, he's lead and Linda backs him:
"Get Up Kate" (Troubadour 1971)
These sound good to me - wish he would do a duet or two for real!