The Catalan star’s epic new single is delighting and dividing classical music fans in equal measureThe Top 10 of today’s Spotify Global Top 50 looks like business as usual: two Taylor Swift songs; Lady Gaga and Bruno Mars’ Die With a Smile hanging around for an eighth month; the eminently normal male pop stars Sombr and Alex Warren doing brisk business.But nestled among the crowd-pleasers is something of an outlier: a gothic, baroque assault powered by Vivaldi-style strings and operatic singing...