Nope. Nothing to say. Sure, I could nit-pick and find a bit here and there that might be tweaked to flow better, but why bother? The flow is brilliant and you've so perfectly encapsulated this moment to me. This is how it is to look upon someone you love -- be they a friend, lover, or even a child -- as they are sleeping. Your imagery is beautiful.
There's this one line that just keeps sticking out to me -- the way you used "lush" is just-short of perfect (and only because I refuse to call anything perfect). There are little things, as far as flow, that could be smoothed out here and there -- longer sentences you might want to play with breaking up. Pay attention to the length of the sentence versus the length of the piece -- if it's to remain a prose piece this short, you really shouldn't need any semi-colons, for example (although you use them well when you do). You've not enough weight for such complex sentence forms. I realize this is a rather idiosyncratic way to look at prose formation, but this is my review. Bygones.
If anything, this would be lovely if drawn out further. You've got several layers here -- the garden, music, and the physical layer of two people lying together. To see each drawn out and more exposed would really extend this piece into something more substantial.
As it is, I almost think it might be better as a poem than as a prose piece -- if not expanded. Even as a vignette it only teases a certain depth I know it's capable of achieving. Personally I'd love to see it in a fuller form, but I'd also like to see what could be done with it poetically as is.
In short, it is perhaps the perfect thought stream, in the sense that you had an idea which has the potential to travel in many different directions and be expressed in so many different forms. As it is, it was a joy to read. As much as you might read works of love, this was a refreshing read that didn't tread the same worn paths.