Put away your trusty summer playlist -- the White House just released two, one for day and one for night, hand-picked by President Obama.

At a groundbreaking press conference in New York City today, Jay Z was joined by a huge group of musical superstars to announce the official relaunch of TIDAL, the streaming music service he recently acquired as part of a blockbuster $56 million deal. Joining Jay Z onstage and as owners of the service were Beyonce, […]