Lianne La Havas, who you should still be listening to, was a longtime Prince favorite. She frequented Paisley Park at His Purpleness’s request, like so many of his protégés in training. And Wednesday night in Copenhagen, she finally got to pay tribute to her late mentor with a little help from Coldplay. The band invited La Havas onstage for an aching acoustic duet of Coldplay’s favorite Prince song, “Sometimes It Snows in April” — the same song D’Angelo fought through tears to perform in Prince’s honor. Few can leave a crowd in hushed awe like Lianne La Havas, but few can also say they were co-signed by Prince. This is one good thing you’ll wish would last.