Jack Johnson has wanted Ben Harper to play the Kokua Festival since the fundraiser's debut in 2004.

Phoned at the last minute that year, Harper pondered a surprise appearance but couldn't make it. A world tour kept him away in 2005.

For Kokua Festival 2006, Johnson simply asked early. Way early.

Harper's gratis performances this week (a Kokua concert happened Wednesday on Maui) are the singer/songwriter/ace acoustic slide-guitarist and multi-instrumentalist's first here in 11 years. And it's a good time for us to get a Harper gig, too.

Harper's seventh album, "Both Sides of the Gun," released in March, is one of the most critically hailed of his 13-year career. A single album spread over two discs with distinct lyrical and musical missions, "Both Sides" is Harper at his chameleonic best.

An intense, swaggering harder-edge disc brews lyrics both spiritually optimistic and brimming with politicized anger in shades of rock, soul, funk, electric blues, jazz and a half-dozen other genres. A quieter, ballad-filled disc has Harper's beautifully wounded falsetto whispering about love, heartache and family ties over his own stripped-down acoustic accompaniment.

Harper, 36, spoke to us about the CD and a few other topics earlier this week from Maui.

I get a feeling listening to "Both Sides of the Gun" that spreading the music over two discs was about returning to the feeling listeners got from a vinyl LP, of flipping that sucker over and communicating a whole other vibe.

"Yeah. ... But it was basically a mood situation where I just felt, out of necessity, a connection to separate the moods of the music for clarity. ... The deeper I got into the recording process, the clearer it became that I was either making two separate records or a double record. ... I had really good luck in the past sequencing diverse records, but on this one the moods were just distinctly different."

"Better Way" has a "Give Peace a Chance" vibe. Was John Lennon an influence?

"Yeah, (he) was a very big influence on that song. All the way to that scream (on it). I don't think I would've had the backbone to do the scream if it weren't for the patented John Lennon scream that made its way to (his) recordings."

Then again, a friend of mine said he got a definite Prince vibe from that scream.

"I love parallels who are people that I listen to. So if there's a piece of Prince in there, I consider myself lucky for that. ... He's got stock in that scream as well, for sure."

My favorite song on the CD is the title track. The lyrics are angry and serious — taking on the current political establishment and the havoc it has wreaked. But that funk groove under it ... you can't tell me I'm supposed to feel guilty for wanting to move to that.

"Oh, man, heck no! Shake it! Without a doubt. ... I think with that whole side of that disc, if you're willing, the music is ready and able when it comes to shakin.' "

Is the CD a partial glimpse into your music collection? I sense some Rolling Stones, some Curtis Mayfield, Sly and the Family Stone, some Paul McCartney ...

"Oh, absolutely! ... I've got everybody from Phil Ochs to Richard Ashcroft to A Tribe Called Quest and Nina Simone in my record collection and in my iPod. ... (I) and my band The Innocent Criminals (often) trade iPods for a week. Everybody just swaps up iPods. Next thing you know I'm listening to Kraftwerk."

I'll bet you made a lot of mixtapes as a teenager.

"Yeah, I've made a couple of mixtapes in my day. Some to say 'hello' and some to say 'goodbye.' ... It could be anything from John Coltrane to Enya ... probably on the 'goodbye' (tape). ... It could be The Beatles' 'Revolution' (on the 'hello' tape). There was always (Led) Zeppelin on my mixtapes. I remember that. They worked well for 'hello' or 'goodbye.' "

The steel slide being your signature instrument, you must own some ki ho'alu recordings.

"I do. Oh, yeah. I have the entire catalog of the Sons of Hawai'i — Gabby (Pahinui) and Feet (David Rogers) — as well as probably everything Sol Ho'opi'i ever recorded. ... I've got some Sonny (Chillingsworth) and Gabby's kids' records, as well — Cyril and Bla. Brilliant musicians! They're on all the time. I've got them on vinyl. Whenever I'm diggin' it, there's nothing that can replace that mood. There's nothing you can't do to Hawaiian music. ... I think I've got everything (Pahinui's bands) ever recorded. I've got bootlegs of theirs. Once people find you're into that kind of stuff — especially here in the Islands — it just comes out of the woodwork."

How did you go from meeting Jack to winding up adding that now famous lap slide to "Flake"?

"Jack and I met for the first time in 2000 backstage at the Santa Barbara Bowl. ... He was just hanging out. I don't think he had recorded a note at that point. He was just coming to the show. And he was with a whole crew of really well-known surfers. ... We just hung out. ... They were really heartfelt into the music that I was making. ... Not long after that show, a mutual friend of ours handed me a tape of 12 of his songs, just acoustic stuff. The tape got handed to my manager/producer (J.P. Plunier) ... and the next thing you know Jack was working with him on his first record. ... (On 'Flake') J.P. was going to get someone else to do (the slide) ... and I said, 'You better not get anybody else to do it! The song's too great.' I was actually offended that he thought about calling someone else. Nobody could have played what I played on there."

Agreed. What's your relationship with Jack like now?

"The best part about (my relationship with) Jack is that it hasn't changed a bit. It's exactly the same as it was, which means it's a true friendship. ... Jack's personality is kind of crazy. He's like a younger brother to me. Him and my younger brother Peter? These guys are identical. ... I've told him that."

What's gratifying to you about his success and how his music has found an audience in an industry usually dead set against giving a chance to anything left of mainstream?

"It means that there's hope. It means you can make music that's against the grain and outside the commercial mainstream and demand that the commercial mainstream come to you. He's living proof that that happens ... without compromise."

Did he learn that from you?

(Laughs) If I had anything to do with that ... I'm proud of it."

Reach Derek Paiva at dpaiva@honoluluadvertiser.com.