When it was founded in 2007, SoundCloud was primarily focused on enabling file-sharing of original audio tracks, and basic collaboration among artists. The two co-founders came from music backgrounds; indeed, in early interviews they compared their fledgling platform to a musician's version of Flickr or Vimeo. From the start, SoundCloud's embeddable waveforms differentiated it from MySpace, which was soon to begin its vertiginous fall from authority. With this week's relaunch, SoundCloud aspires to more than a gleaming redesign, though it definitely brought out the silver polish for this refresh. The new Sound