This collection is such an amazing treat, what The Edge refers to as the U2 sketchbook. As he writes in the liner notes, "these ideas are often the most revealing of their time because they are the least worked on songs and recordings. For this reason, they are some of my favourites".
I couldn't agree more. Stretching from 1987 to 2004 these rarities provide an incisive look into the recording sessions that would bring us the finished albums we have come to know and love so well. You can hear possible hints for the sonic direction of the given era as well as some risks and experiments that, while not making the final cut, certainly make for an interesting listening experience. This is a thoughtful and much-appreciated offering from U2.