As he prepares for another solo acoustic Songbook Tour and the release of a "Songbook" album, Chris Cornell says he's embraced a spirit of spontaneity and improvisation for these shows.

"I rarely use a set list," the Soundgarden frontman tells Billboard.com. "If I had done, I'd rarely follow it. I'm lucky to get three songs out before I completely deviate from whatever it was that I was going to do -- to the point where I don't really plan anything. There are points in the set where I'll do a song because it's where I want it to be. It's really something that we're figuring out."

"Songbook" will be released in three parts beginning with "Songbook EP 1" out Nov. 1, and "Songbook EP 2" following on Tuesday, Nov. 15. Listen to "Songbook EP 1" Here FIRST:

And by "we," Cornell says he means himself and the fans who come out for the show.

"It blows me away that there's this willingness by an audience -- continually, night after night, just all over the country and even in different parts of the world -- to sit and listen to a guy singing a song and playing acoustic guitar quietly, and not making a sound," Cornell says. "And then between songs they're shouting out (requests) and actually having a conversation with the guy that's on stage. It's really something I didn't expect, and it's something that I really like. I didn't realize it was going to be as special to me as it is."

Cornell says he hopes the Nov. 21 "Songbook" album -- featuring 15 songs recorded during his spring tour plus a studio version of "The Keeper" from for the film "Machine Gun Preacher" -- captures that spirit of his early shows. "I wanted to get the infancy of this out there, because it's very sparse, very rough, very new," Cornell explains. "All I was concerned about was finding versions of the songs that sounded like it felt like they sounded when I was there. It was something I wanted to give back, and I wanted to do it right away because I was just really knocked out by how it was received."

The "Songbook" album includes the mix of Soundgarden ("Fell On Black Days," " "Black Hole Sun"), Audioslave ("Wide Awake," "I Am the Highway," "Doesn't Remind Me"), Temple of the Dog ("Call Me a Dog") and Cornell solo songs ("Scar On The Sky," "Ground Zero") that he performs at the shows, as well as versions of John Lennon's "Imagine" and Led Zeppelin's "Thank You," drawn from the wide array of covers he's done.

"Those are usually born from me just sitting around and rehearsing or sitting in a hotel room and just thinking about a song or warming up my voice or things like that," Cornell says. "Sometimes it's just on a whim; 'I wonder how this would sound acoustically?' and I feel like it's something I would want to do live. And sometimes I'll pull something out that I don't actually really know and just sort of do it from memory."

Cornell hits the road again by himself on Nov. 1 in Memphis, sandwiching four South American shows into the 30-date itinerary that also includes a Nov. 21 stop at New York's Carnegie Hall and wraps up Dec. 17 in San Diego. After that, Cornell returns to work on the reunited Soundgarden's new album -- its first studio set since 1996 -- which he says will likely come out in the spring of 2012.

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"It's mostly done," Cornell reports. "We just need to finish a couple of songs and mix it, so that will be happening probably over the holidays."

As to what it sounds like, he says that, "It's certainly not nostalgic. It's definitely forward. It sounds to me exactly like it should sound -- like we took a break and we got together and we're making an album. I don't think we've taken any dramatic new approaches to writing or recording, and yet there's definitely changes. We've all had a decade-plus of more experience in writing and recording and took a long break... So it's very refreshing and it feels to me like the next logical step in Soundgarden, creatively."

Audiences at the upcoming Songbook Tour shows shouldn't expect to hear previews of any of the new songs, however. "I think it's definitely a Soundgarden record," Cornell says, "and I wouldn't want to take it out of that context just yet."