I sat in on the Future of Music Delivery Keynote interview with Spotify CEO Daniel Ek and author Eliot Van Buskirk on the last day of SXSW Interactive. Buskirk's covered the digital media industry for ten years in various publications. This keynote was not nearly as crowded as the Evan Williams one was at the beginning, but definitely kept a lot more people hanging around through its entirety. The first part of the keynote was essentially a product demo for Spotify,