The new logo, seen below, first popped up in Spotify's new TV ads. The logo has since been integrated on Spotify's website, though Spotify's apps have been updated to use a new logo based upon the new design. Spotify will likely adjust the logo with the next update released to the apps.
What do you think of the new logo? It's most likely been changed due to Spotify's redoubled efforts to expand its userbase. The new logo is streamlined and cleaner than the old logo and definitely looks more professional. We'll see if it helps Spotify expand in the United States and abroad.