In time, what was a disruptive technology becomes a part of our life that we don't even notice. One hundred billion units later, cassette tape is one of those technologies. It kicked off the ability to personalize the curation of music. You can draw a straight line between those tapes and Spotify playlists. Lou Ottens, the engineer who created the cassette tape, died recently. Ottens also helped create the compact disc, which ultimately killed the cassette tape. His obituary is a reminder that only very few are fortunate enough to create technology that touches everyone's lives. Read the obituary on Open Culture.