Singer-songwriter Brandi Carlile's third album, "Give Up the Ghost," is a dream -- or dreams -- come true, in more ways than one.

The songs themselves, Carlile tells Billboard.com, were inspired by "really vivid, poignant dreams" that she'd log in a journal when she woke up and subsequently turn into songs. "Your subconscious tells you so many more interesting things than what you conscious mind tells you day to day," she contends.

Then there's the Oct. 6 album's guest list, which Carlile says went beyond even her wildest dreams.

The big catch was Elton John, who joined Carlile on the track "Caroline." "He's my greatest influence since I was really young, about 11 years old," says Carlile, who also used John associate Paul Buckmaster for string arrangements on the album. " 'Tumbleweed Connection' is maybe my favorite record of all time, that or 'Captain Fantastic...' We felt like 'Caroline' had the same funky piano vibe that he had all the way through 'Tumbleweed Connection.' We went through the channels; I knew the worse he could do was say no. He didn't say no. He said yes.

"He responded directly to me, called me on the phone one morning. I was just like, 'Man, this guy, he is just no bullshit. He is so cool...' He was unbelievably funny and warm and stuck around for a long time after he was finished and schooled me on new music that was coming around the band. I've never been so inspired."

Carlile also tapped Red Hot Chili Peppers drummer Chad Smith and Benmont Tench from Tom Petty's Heartbreakers for the "...Ghost" sessions, and she shared the vocal mic with Indigo Girls' Amy Ray, who Carlile calls "my dearest friend," on the song "Looking Out."

"She actually sang the background vocal live in the booth with me, which was really cool," Carlile says. "A couple times she laughed at me really hard when I missed some notes. It was really fun."

Carlile is promoting the album with her Give Up the Ghost Traveling Show, which runs through Oct. 24. She'll perform on the Cayamo: A Journey Through Song cruise in February and is also planning European dates.