When Marina Diamandis christened herself Marina and the Diamonds at the start of her career, she joined a long and noble history of solo musicians giving themselves group names. It’s a decision that she has since questioned. “Bloody hell, over the years I’ve explained it so many times,” the Welsh singer says with a laugh. “I’m like, ‘God, I wish I’d just chosen Marina Diamandis. It’s so much easier.’ But there’s something friendly about having ‘and the Diamonds.’ ”  All three Marina and the Diamonds albums have cracked the UK Top 10 (2012’s “Electra Heart” hit No. 1), and the new “FROOT” — with its mix of grownup dance-pop and melancholy confessionals — has finally followed suit in the United States. Marina and the Diamonds join Boston Calling’s Saturday lineup riding that wave of momentum. “It’s actually been way more low-key on the American side, so that’s been a surprise to me,” says Diamandis. “You know when an artist goes, ‘Oh, I totally can’t believe it happened,’ and you think, ‘Yeah, right, of course you didn’t.’ Well, it’s actually true. Sometimes things happen and you really don’t expect them to, and it’s all the nicer for it.”  Q. You’ve described the way you relate to music as a form of synesthesia. Are you speaking figuratively, or do you genuinely see music as colors?  A. I mean, obviously there are varying degrees of synesthesia, but the way that I experience it is that I connect color with musical notes, with days of the week and numbers. But I never think about it except when I get asked about it. I think it was about eight years ago, I realized that most people don’t do that. But it’s not something that’s extreme. It’s more having a sensitivity to color and relating to it heavily.  Q. You’ve played opening slots on giant arena tours with Katy Perry and Coldplay. How do you change your performance for shows where it’s the opportunity to introduce yourself to people instead of headlining your own shows for your own fans?  A. It is completely different. You’re constantly trying to convince people to look at you and to pay attention to you, which is not my complete cup of tea. So I’m glad those days are over. But they did help, and you do learn to adapt for different types of audience and also different sizes of audience. Festival performances are one kind of thing. They are different from the headline shows that I do, in terms of energy, because you’re addressing a huge crowd who might be big fans but they might not all be diehard. The headline shows are always really intense and extreme energy, whereas festivals are much more loose and more chill.  Q. The metaphor in “Froot,” the song, is not exactly subtle. Did you ever wonder, “Is this a little too blatant, what I’m talking about without quite talking about it?”  A. Well, go on. Why don’t you say it and see if it’s true? [You could] probably just say, “Does it have sexual connotations?”  Q. I mean, when you’re singing about the juiciness of your fruit, it seems to be about what I believe old Hollywood producers used to refer to as Topic A. Am I reading too much into it?  A. I don’t know. I mean, quite honestly, when I was writing the song, the main theme was that I felt really ready to be happy, and I really wanted to enjoy my life and embrace things. I felt very ripe and ready as an artist as well. I was very much ready for things to happen. So I was using fruit as a metaphor, I suppose. But I was also talking about love. So yeah, it’s a bit of both, really. I completely understand why people would be like, “Oh, my God, it’s a quite sexual song.” But that wasn’t the root of the song.  Q. “FROOT” is your first album with no co-writers and only a single producer. How did that affect the work?  A. I think what I feel is that it’s a purer representation of what I’ve been trying to do and wanting to do over the past five years. I think when you’re writing alone, usually you write slower. So it’s not a case of going into a studio in LA and doing a song in two days with someone. It’s more thinking about concepts and I suppose ideologies, in a way, and philosophies about my life and how I felt at the time of writing it. And sometimes that takes time. It can take a few months to collect lyrics and thoughts for a song. When you have a co-writer, you don’t get the chance to really do that. So in effect, you get a different kind of body of work. And it’s not that it’s not your work. It’s just very different.  Q. Did it feel at all like you would either sink or swim by yourself for the first time?  A. Yeah. Not that I’d sink or swim, but I did definitely feel like I didn’t have to write for anyone else anymore. Or rather, I didn’t have to write the type of songs that people were hoping that I would write. And that is very satisfying. It’s very confidence-building, actually, when you realize you actually don’t care anymore about being popular. (Laughs)
Marina and the Diamonds takes the stage at the Boston Calling Music Festival Saturday, riding the success of her new album “FROOT.”