4.5 Just because I felt like the piano only section at the beginning could be half as long, imo, for this to be relatively stand alone; I was starting to get bored before the rest of it kicked in ... and then it was all ear candy after that. Aaaah. Of course it would very much depend on how this was being used, and the lack of a real ending leads me to believe you'd expecting to adjust the length etc to whatever actual purpose it might be used for.