Piers Morgan told Lindsey Stirling that her playing sounded, at times, “like a bunch of rats being strangled”. Sharon Osbourne said that Stirling needed to start a band, with a singer, because a dancing violinist was never going to fly as a solo act.

That was in 2010, when Stirling, billed as a “hip-hop violinist”, appeared on America’s Got Talent, playing along to Taio Cruz’s “Break Your Heart” and Ke$ha’s “TiK ToK”. Almost four years later, Stirling is having the last laugh. As of this writing, the Los Angeles–based performer’s YouTube channel has more than 5,000,000 subscribers, and has racked up close to 700,000,000 views. Her second album, Shatter Me, was released at the end of April and debuted at No. 2 on the Billboard 200.

On the phone from New York, where she’s doing a day of press, the 27-year-old musician says that being on America’s Got Talent didn’t have much impact on her career, apart from possibly earning her a few extra YouTube subscribers.

“It’s not like that show, at least in the moment, did anything for me,” she notes. “A lot of these reality-TV shows, people go on, they come off, and nothing happens. You never hear from them again. Fifteen seconds of fame is not the name of the game. No matter how big you break, or how many people you break in front of, you still have to slowly build a fan base in order to have anything loyal and anything lasting from people. At the time, I thought, ‘Wow, it’s like I never went on the show.’ And then, thank heavens, I started building a fan base much more organically, my own way.”

Doing things her own way has worked out just fine so far. Given the success of Shatter Me and Stirling’s self-titled 2012 debut, it’s only natural that labels of all sizes have come calling, but Stirling cherishes her independence too much to sign it away. “I love being able to have 100 percent creative control over all my music, and it’s just really awesome that I get to make all the decisions,” she says. “I don’t have any pressure to do it this way or that way or conform to one way or another. It doesn’t have to go through this huge chain of command anytime I want to make a creative decision.”

It’s anyone’s guess what a major-label A&R department would have made of the music on Shatter Me, which is an alloy, Stirling says, composed of equal parts classical, Celtic, EDM, and hard rock. Songs range in style from the trance-inspired thump of “Mirror Haus” to the bass-bombed dubstep of “Heist”. The most obvious nod to rock is the title track, on which Stirling’s elegiac melodies share centre stage with the voice of Halestorm singer Lzzy Hale for what sounds like Evanescence inventing baroque-step.

“There are a lot of people who like to put their finger on exactly what it is they’re hearing,” Stirling says. “I have always kind of been the opposite. I never liked feeling like the world needed to have labels on everything, whether it’s people or categories of music. I just think everyone should be what they want to be, and you shouldn’t have to look a certain way in order to fit this mould or that mould. And so I kind of feel the same way about music. I love being able to express all kinds of different things.”

Lindsey Stirling plays the Pemberton Music Festival on Sunday (July 20).