“Given that the cassette is widely regarded as a nostalgic curio today, few people were surprised when Sony discontinued production of the Walkman, their once-iconic portable cassette player, last April. The greater shock, for many, was the realization that Sony was still manufacturing Walkmen at all. While we mourn the player’s death and await the iPhone 5, it would be a mistake to dismiss the cassette as merely a transitional technology. Rather, it offered its user a previously unimaginable degree of autonomy, a freedom that is today familiar to us, and was the first music format to raise thorny questions about the concept of fair use and about what it means to own a piece of music.”