I thoght the Allison Krauss/James Taylor duet of "How's The World Treating You" was harmony magic. Wish they would consider a whole album together.  Also would like to hear Allison do another album with duets in it I think she and Brad Paisley did a great job. Would like to hear her team up with Ricky Van Shelton, the girl singer in the Time Jumpers or whatever the name of that group is {that girl can stand flat footed and sing}they sing a lot of Texas swing and stuff.  I'm not into some of K.D. Langs lifestyle stuff but she is an outstanding singer to, bet she and Allison would sound good too. I love folk music and the accoustic stuff in some of Allison's work is fantastic. Saw where she and Mary Chapin Carpenter were going to both be at some event they would make a fantastic duet I bet.  I don't know what the song would be but would like to hear something from Marty Robbins collection with a liitle of  the mexican flare he had in his music. He is one of my alltime favorites. Like the fact that Allison mixes some gospel music in her stuff and think she and the Isaacs harmonizing on a quite gospel song would be wonderful. Just stand up there with minimal accoustic background and flatfooted sing. Underwhelm the audience if you know what I mean. Maybe include something form the "The Singing Rambo's" another alltime favorite group of mine.