Definitely not 'Blue Shimmer', though the pattern is similar. 'Blue
Shimmer' has a much older look (it is old), with less ruffled and narrower
flower segments. Judging from the photos, 'Blue Shimmer' is a more
"vertical" flower, due to the slightly less spreading narrower segments.
The falls definitely hand down a bit more. 'Blue Shimmer' is a beauty, but
I'm one of those weirdo's who loves that old-fashioned shape.
Can't say yes or no for the name 'Jessie's Song', as I don't have any
photos to compare, and can't remember it clearly. Might do some Googling
I'd like to know what it is too, because it is another of rather few
"modern-looking" ones that definitely got my attention.