Absorbing chronicle

There’s a startling moment in “With the Lights Out,” a rich trove of unreleased Nirvana tapes which will be released Tuesday as a box set.

It comes just before Kurt Cobain begins singing “Rape Me” – a song so full of dark, violent imagery that MTV executives once warned him they’d switch to a commercial if he sang it on an awards show.

It’s the sudden, sharp cry of a newborn baby. The image is striking and poignant – the most important figure of his generation in American rock, weeks-old infant on his lap, singing the wounded reflections of a man who felt violated and betrayed.

There’s no explanation in the liner notes as to why Cobain’s daughter, Frances, was at his side that day.

Was Cobain keeping the infant at his side to make sure she felt the love he’d missed? Did her presence strengthen him to dig deeper to express the anguish and alienation of the song?

Thanks to intimate and evocative moments like this, “With the Lights Out” is a modern pop rarity: one of the few retrospectives that doesn’t seem like merely a greedy marketing device.

It’s a warm, absorbing chronicle of the creative process of a writer whose introspective songs examined the uncertainty and longing of adolescence with an uncommon understanding and grace.

In addition to its various home tapes, studio practice recordings and radio station appearances, “With the Lights Out” uses more than an hour of video footage to follow Cobain’s musical growth.

Cobain hated it when he was called the “voice of a generation” – a frequent label after Nirvana (whose core lineup also included bassist Krist Novoselic and drummer Dave Grohl) began selling millions of albums. Yet the lesson of the box set’s 81 tracks is that Cobain always was on a mission.

Even in the ragged recordings from the band’s infancy, you sense Cobain searching for a way to tell his own story, not just fit in with the rock scene. “Nirvana has never jammed on ‘Gloria’ or ‘Louie Louie,’ ” he said in an early interview reprinted in the liner notes. “Nor have they ever had to rewrite these songs and call them their own.”

Placed back to back, the songs on “With the Lights Out” – some of which never appeared on Nirvana albums – show how Cobain honed his style by combining the melodic charm and delicious pop hooks of the Beatles with punk defiance and a vulnerability that was rare at the time in hard rock.

We hear the evolution of Cobain’s vocal style as he delivers seemingly heartfelt emotion with a sarcastic edge or expresses upbeat lines with a sad helplessness. Life for him was too complex to be presented in orderly fashion.

The set ends with a particularly moving version of “All Apologies,” a song that would appear on Nirvana’s 1993 album, “In Utero.” It includes the lines:

“I wish I was like you/ Easily amused/ Find my nest of salt/ Everything is my fault.”

After finishing the song, Cobain reaches over and turns off the tape recorder and the silence is jarring – a reminder of all that was lost when he committed suicide in 1994 at age 27.

There has been so much shameless repackaging in the music industry that there’s reason to be suspicious of retrospectives such as this. But “With the Lights Out” is a special case – and not just because it carries the blessings of Novoselic, Grohl and Cobain’s widow, Courtney Love.

Much of Cobain’s greatness came from his insistence on seeking his own voice. The wonder of these tapes is they let you follow him on that search.