Beyoncé took to her social media accounts Saturday to tease a mysterious new project, dubbed "Lemonade." It's unclear what the singer is referring to ? whether it's a music video for a new song or the debut of something even bigger ? but Beyoncé advised fans to tune into HBO on April 23rd at 9 p.m. Beyoncé has previously teamed with HBO to broadcast her and Jay Z's 2014 concert film On the Run Tour as well as her 2013 documentary Life Is But a Dream.