Kate I think it is very likely she will be there ( he has raved about her considerably and would look very strange if she was not there) - it doesn't give Jodie by name, so it is unlikely to be just Jodie, although Jessie may not sing solo - it may just be a group number with all the girls.
It would appear that this is a celebration of ALWs work, so suspect most things will be songs he wrote. I am not clear how long the concert goes on for and will therefore depend on how many songs there will be time for. To be honest, the line up is so good, although it would be really disappointing if for some bizarre reason she wasn't there, it will still make for a riveting evening. Find it strange that Connie Fisher's name is not on it - was this an oversight in the printing, or is she not singing?