(CNN) -- Jason Mraz pulled up to the studio near Burbank Airport on his scooter, like a kid anticipating the start of a new school year.
But in this case, it was the first day of rehearsal with his new band.
"I invited a lot of people to come audition, a lot of people that I love and have always wanted to work with, but I couldn't hire everyone," said the San Diego-based singer-songwriter. "I could only fill five positions. It felt like I was breaking up with people. I had to call people and be like, 'I'm sorry, it's not going to work out.' "
The break-up theme is front-and-center on "I Won't Give Up," the lead single off of Mraz's fourth studio album, "Love is a Four Letter Word."
"It's not a break-up album. It was certainly written at a time when I wasn't certain what was going to happen inside of a relationship," he told CNN, settling into a couch.
He's referring to his broken engagement to fellow singer-songwriter Tristan Prettyman. But the two-time Grammy winner says the message is more figurative than literal.
"It's an album of love songs, but not just through the filter of romanticism. It's also through compassion and empathy and love of our natural world. At the end of the project, I still didn't feel like these 12 songs summed up what love is. I was like, 'I don't know. Love is a four letter word.'"
And so is the word "tour."
Mraz's "Tour is a Four Letter Word" kicks off on June 8 in Pusan, South Korea, and hits the United States the following month in Honolulu, Hawaii.
In the meantime, he's devoting much of his passion to the newly launched Jason Mraz Foundation.
" 'Jason,' in Greek history, means 'healer,' " he pointed out. "So I really wanted to take that on, not only in my music, but in my work in the world."
The foundation supports a variety of causes, from education and the environment to addiction assistance and human rights. He's also been outspoken about his support for marriage equality.
"Traditional marriage between a man and a woman, and trying to put that into a law or a rule, is basically saying that gay people aren't real. Well, gay people are very real. It is treating our gay and lesbian citizens like second-class citizens. I think it is the final step in the civil rights movement," he said.
For Mraz, that's what his song, "I Won't Give Up," is all about.
"It's about not giving up on a dream, or the integrity of who you are," the singer said. "There is no dream too big or too small. Everyone has one thing that is worth fighting for."