Sprint has a track record of making left-field, even mystifying, decisions. The latest is its plan to buy a 33% stake in music streaming service Tidal for an estimated $200m – even though Tidal is a minnow compared to Spotify or Apple Music, and made net losses of $28m in 2015. Tidal can be accessed in 52 countries, but is not making an impact outside the US. This looks like a desperate attempt by Sprint to slow the momentum of T-Mobile USA, which offers Music Freedom as part of its Binge On service, allowing users to stream music from all the major players without being hit with overage charges. Its partners include Tidal itself plus Spotify, Apple Music, Pandora, Napster,…