When singers create albums, they spent months -- sometimes years -- getting everything just right. They devote themselves as fully as possible to the project. They put all of their creative energy into the lyrics, the melodies and so on. Crafting a new body of work is no easy feat, so to craft two bodies of work, which are separate but related, at the same time is a truly tall task. And yet, David Berkeley has done it ... twice.

In 2011, the singer-songwriter, who has a degree in literature from Harvard University, released Some Kind of Cure, an album inspired by a year spent in Corsica with his wife and young son. In tandem, Berkeley released 140 Goats & a Guitar, a book that chronicles his family's travels and the anecdotes that inspired Some Kind of Cure's songs. Four years later, in September of 2015, the 39-year-old did it again: He released his sixth album, Cardboard Boat, and its corresponding book, The Free Brontosaurus.

Books, whether mostly true (as 140 Goats & a Guitar is) or totally fiction (that would be The Free Brontosaurus), are a logical extension of Berkeley's music. In addition to his literature degree, the artist found himself feeling less shy onstage when he started setting up his material with stories.

"A lot of my material, it's fairly heavy and deep ... so I found that I wanted to lighten my shows," Berkeley tells The Boot, admitting that his sets have since evolved into "half standup, half concert."

The first time around, Berkeley crafted his songs first, then wrote down the stories -- and he was writing from firsthand experience. With Cardboard Boat and The Free Brontosaurus, however, his process was slightly different: The stories influenced the songs just as much as the songs influenced the stories -- and Berkeley was creating the characters and tales from thin air, so to speak.

Berkeley estimates that he spent about four years putting both projects together, but, in some ways, it was easier to write fiction; for example, he notes, "I think it was easy to empathize with these characters" and craft their stories and songs. Additionally, he enjoyed being able to tell tales that weren't his own, using protagonists who are different than himself to relate with a wider audience.

While Berkeley has "always been involved in music in some way ... it's always been something I've cared deeply about," he never saw himself being a musician; however, he was also never interested in "some of the more conventional paths" and found himself "always drawn to more expressive pursuits." He first wanted to be a travel writer -- in fact, he even did some travel writing during and just after college -- but Berkeley ran with a musical crowd: At Harvard, he managed a band featuring his friends, and once he started writing songs of his own, he couldn't stop.

"Mostly because it was a challenge, and it was hard to master," Berkeley explains. "I was kind of constantly trying to better myself through that and figure out better ways of capturing what I was seeing or feeling.

"It sort of felt like an endless goal," he adds -- "something that you could really devote yourself to and never get bored of, and, to a large extent, that's proved true."

Berkeley released his first album in 2002. In the mid-2000s, he toured with Nickel Creek, and has remained friendly with the band. That connection came in handy when Berkeley needed a woman's voice to bring the songs corresponding to his female The Free Brontosaurus characters to life. The band's Sara Watkins sings five of Cardboard Boat's 10 tracks.

"i've always thought that she had the most incredible voice," Berkeley gushes of Watkins. "... She can embody so many different emotions in her voice."

Fans will have to do some detective work to determine how the songs on Cardboard Boat and the stories in The Free Brontosaurus match up; their orders are not the same. The stories themselves needed to go in a certain order, but putting the corresponding songs in the same order "would make a weird record," according to Berkeley. Mixing the songs up meant that fans can enjoy each work separately -- and that both the record and the book are the best they can be.

"That's the challenge of this project ... I don't make it easy for people," Berkeley says. However, a forthcoming audiobook ("the perfect realization of this idea," in Berkeley's words) will match up the stories with their songs, for the fans who want to know.

After spending so long on this two-part project, Berkeley isn't sure what's in store for his next release. In the future, though, he's open to creating another book-and-album combination; specifically, Berkeley thinks a children's project sounds like fun.

"I think that it's a really neat idea to give people more of a world that just the songs," he says.

Cardboard Boat and The Free Brontosaurus, both individually and as a set, are available for purchase through Berkeley's official website.

The Making of Cardboard Boat