Greg Bear writes some of the best sci-fi out there, and this is some of his best work.
Blood Music, without spoiling anything, is about different forms of intelligence, about something alien to us, about biotechnology and experiment, about humans and how we cling to our notions of normal and the "self". It deals with all of these questions, and weaves them into a beautiful story.
Blood Music is filled with unique ideas. Ideas that make you think about the possibilities of what the future could hold. Just like good SciFi should.
I don't want to spoil anything from the story, so just grab a copy and start reading.