Let Her Go topped the charts worldwide and has sold more than a million copies in the United Kingdom, plus another four million in the US.
Stopping in Auckland for a quick promo tour ahead of his NZ tour dates in January, Rosenberg reveals his new album Young As The Morning, Old As The Sea has a special Kiwi connection.
"I love New Zealand and I'm not just saying that. Before Let Her Go happened, I busked a little bit here in New Zealand and I've always liked it.
"Two years ago I was touring here and we had to record something really last minute and we ended up at Roundhead studios. We were only there for the day but I fell in love with the place."
So much so that he decided to record part of his album here.
And the Kiwi connection doesn't end there.
"I spent a bit of time on the South Island before going into the studio and I think that definitely kind of put me in this really good headspace to record. I think there is a lot of New Zealand that's come through in my tracks. It's so amazing down there. I loved it.
"In the past I have always written about people. It's always been my inspiration. But this one, although there is a bit of that, there's strong references to landscapes."
As for the album's title - Young As The Morning, Old As The Sea - Rosenberg says it refers to his own life. "It's my eighth record and I am 32 now and it just feels like I'm at an interesting point where I still feel very young and silly and naïve but I also feel like I have done lots of experience-building."
He'll be back to build more experiences in New Zealand next year, returning to Auckland and Wellington for two shows.
It will be the first time he's performed here with a full band, enlisting the help of the musicians who worked on the album with him.
"I have been playing solo forever and I do love it but I just feel like with this record it's a bigger arrangement and the songs need a bigger idea behind it.
"I also want to give people a completely different show so they can hear these new songs and the old songs with a full band behind it. It will be a really different challenge for me and that's always a good thing."
LOWDOWN: Who: Mike Rosenberg, aka Passenger What:Young As The Morning, Old As The Sea out tomorrow Tour: Playing Auckland's Civic Theatre on January 17 and Wellington's Opera House on January 18.