And Robert has now said he and Alison had always planned on getting back into the studio together but had just never found the time in their schedules.
When asked why the pair chose to reunite, Robert said, "We'd always wanted to do this. When the previous project came to fruition, she went off in one direction and I stayed in America and formed a group called the Band of Joy, and I went off on the road again. I love playing. As long as it's good fun, there's no better place to be."
"So we both did individual stuff, and we'd meet now and again or speak on the telephone like, 'How about this?' or 'Have you heard this song?' "
And because we come from different areas of music, our appreciation of parts of the music spectrum are radically different, so it's almost a learning curve just discussing stuff with her.
"But we never ever had the time (to make a second record). I was really happy doing what I was doing and she was happy too. Then we met when we were all still furiously working and we ended up on a show with Willie Nelson in America, and I listened to her sing again and I thought, 'Man, there's gotta be room, let's do it.' "
Robert is excited for his and Alison's new release, and has come up with a new genre for their unique material called "dark and spacey."
Speaking during an interview on BBC Radio 2, he added, "The wonderful thing about it is that it's nameless, and it has its own personality."
"You could say it's kind of a little bit retro sounding. It's almost an archival study of pretty far-out spacey music. I think you could call it dark and spacey."
"Raise the Roof" will be released on 19 November (21)