NEWPORT — Melissa Etheridge’s voice is still a raspy, gutsy wonder — she sang better last night at the Snapple Sunset Music Series than she did on the records of her mid-’90s hit-making heyday — and her head-thrown-back, acoustic-guitar-thrashing image is becoming nearly iconic. And last night all her strengths were on display in a show that was unusually structured, to varying effect.

The two-hour show arranged songs from the beginnings of her career through her latest album in roughly autobiographical order — an idea loosely inspired by her latest record, last year’s The Awakening, which took a look back at her life. Etheridge also put in spoken introductions to many of the songs and even a few spoken passages in the middle of tunes, such as “I Wanna Come Over.”

So we got the stories behind songs such as the new “California” (“I never knew places like [Newport] existed” during her childhood in Kansas), which stood out for its lovely talismanic use of the title. We heard about “relationship trouble” before “No Souvenirs,” and more of it before “Bring Me Some Water” (“a non-monogamous relationship, that’s just trouble. … But it makes for good rock ‘n’ roll songs”).

And of course, the story of recent years includes Etheridge’s breast-cancer diagnosis and recovery. She introduced the cancer-research anthem “I Run for Life” by saying that “Cancer isn’t very rock ‘n’ roll. Well, I proved it is,” before describing what her research taught her about the genesis of the disease.

It began to approximate The Melissa Etheridge Story, a staged reading of a musical theater piece starring Melissa Etheridge. Still, Etheridge’s life story, as related in last night’s show, is at once unusual enough to provoke curiosity yet common enough for most people to identify with. (And her plainspoken, self-effacing personality is also winning.)

Etheridge detoured into the political with the Oscar-winning “I Need to Wake Up,” from An Inconvenient Truth, and “Kingdom of Heaven,” taking to task religious extremism of all types. She also included “Message to Myself,” a song from the new album about looking back and looking forward, before finishing up with the hits “I’m the Only One,” “Like the Way I Do” and the encore “Piece of My Heart,” which she famously made her own at the 2005 Grammy Awards.

What the show didn’t accomplish was what Etheridge described as her goal in an interview last week — to break down barriers between the performer and the audience; except for a little extra talking and maybe a few more new songs than usual, it was basically a normal show. Part of the reason may have been that last night’s set was shorter than her normal show (a decision by the Sunset organizers), which is nearly three hours.

Either way, the image of the adored rock star on the raised stage wasn’t punctured last night; that may simply not be possible, particularly if the audience doesn’t want it to happen (which, last night, it didn’t seem like they did).

On the other hand, two hours may have been enough: Etheridge’s punchy, classic-rock-inspired approach works well in short bursts on the radio, but three hours of her nuthin’-fancy anthems done by her tight but basic four-piece band (an exception being the excellent lead guitar of Phil Sayce) could well have been too much. Humble musical explorations such as the shuffle of “I’m the Only One” and the minor-key ballad “Kingdom of Heaven” stood out for their novelty.

In sum, it was only rock ‘n’ roll, but we liked it.

rmassimo@projo.com