I've read a lot about Kurt Cobain, plus knew musicians who met him or people who knew him well. He really doesn't strike me as autistic at all--strong ADHD traits though. I believe he was even dx'd with hyperactivity and medicated with Ritalin as a child.
Courtney Love, however, is very likely a HFA. She was non-verbal as a small child, had several developmental issues growing up, still struggles with social skills. People may like hating her, but I really think she's one of us.
I've written stuff about Beethoven on several Aspergers forums over the years, arguing he had Asperger's. I studied both his and Mozart's music and composition styles indepth as a music major, and Beethoven's style really strikes me as an Aspergian style: very systematic, focused on structure, coherency, and logic, points to strong visual-spatial reasoning. Beethoven wrote music like an engineer--and this is why he could continue to write great music after his deafness became debilitating. LFA/nonverbal HFA may have run in his mother's family: his mother and some of his sibling were "mute" which, although we can't say definitively, could have been non-verbal autism.
Mozart on the other hand does not strike me as autistic. He was an exceptional prodigy, but contrary to how he's portrayed in films, he was actually a very well-mannered, well-adjusted child and didn't seem to have many developmental issues, at least nothing that was well documented. I have a book of his letters, some from when he was quite young, and he had extraordinary grasp of expressive language and language conventions, nothing like I've ever seen in any of my HFA/Aspie students, but I have seen precocious expressive language skills in kids with dyslexia. He was also predominantly an auditory learner, which we know from accounts by his music teachers. That's more like a dyslexic than an autistic too. Mozart's compositional style was very different from Beethoven--unlike Beethoven who created elaborate, reaching, detailed "systems" of music that he labored obsessively over for months if not years, Mozart stuck to very narrow, formal forms that allowed him to compose rapidly and produce a much greater volume of work, and a fair amount of it borrowing from earlier works of his. Only on occasion, like with his operas and his unfinished Requiem, did he really push himself creatively. Mozart often composed a new work completely in his head, only writing it down later so it could be performed--sometimes, if it was the part he himself woudl be playing, he wouldn't bother writing it down at all until someone else wanted to play it. This means his style points to strong auditory and musical intelligence.
Mozart thrived as a musician and a student under private instruction, but Beethoven had a habit of challenging his teachers' authority and skill. Mozart as an adult was noted for his manners and civility, seemed very aware of social norms, and appeared to conform relatively well to the status of a working musician, which in his time was about the same level as any other non-land-owning artisan. Beethoven was quite the opposite--he was considered rude, aloof, difficult and uncouth. He was known to fly into a rage over things he perceived as grave injustices or hypocrisy, such as Napoleon's crowning himself emperor--
Beethoven's reaction was well-documented and evidenced. It seems clear from many accounts of Beethoven's behavior as an adult that he struggled with social conventions and rules, and even openly resented the notion that he was his patrons' inferior in status. He was the first great composer to challenge the norm of seeing working musicians as little more than hired artisans, which dramatically changed how composers were treated from his day on. He was, in essence, the first "rock star" but largely because he couldn't conform to social norms.
So as I see it, Beethoven, yes; Mozart, no. I would suggest Mozart was dyslexic, if he had any real developmental issues at all.
