I interviewed Rosand several years ago when he was traveling through the area for a performance. In talking to him and discussing his extensive links to great teachers and performers he had worked with and encountered in his already long life, I said to him "You're really the last of the romantics, aren't you?". I don't remember his exact words, but his response was something along the lines of "Yes, I am".
In addition to performing, Rosand taught at the Curtis Institute, retiring only three months ago. Pneumonia was the cause of death.
You can find an article about his life and career here.