Here’s a sentence I never thought I’d write. This Friday night in a Bushwick warehouse, almost 1,000 people are gathering to watch a performance of Berlioz’s Symphonie Fantastique, a 19th century piece of classical music. Before you ask — no, this is not a fad (baroquecore?). Rather, it’s an event hosted by Groupmuse, a social media platform single-handedly bringing classical music back into #relevance.