Tango and Spotify are kicking off a collaboration aimed at offering a new music sharing opportunity for Tango messaging app users. Anyone using Tango can get access to 30 second clips of any Spotify song — and then share them with their friends. People can access full-length songs via the music service. Spotify has 24 million active users and according to Tango’s Eric Setton, the company’s messaging app has now hit 60 million monthly active users globally. According to Onavo, Tango lags behind rivals like Kik or Viber in monthly engagement among iPhone owners in the United States. But interestingly, Setton claims that the real-time protocols used by Tango are incompatible with Onavo’s methodology, leading to vastly understated engagement readings. I have heard other developer claims