“Acoustic,” a new collection of John Lennon’s solo demos, outtakes and otherworldly musical particles, is a strange, large-hearted and gratefully-received message from the grave. It is noteworthy for two reasons: the staggering clarity of Lennon’s voice and the superb craft of his song-writing.

Since his death in 1980, Lennon’s music has surfaced in various incarnations, lawfully and illicitly, happily and lamentably. In addition to “Acoustic,” the Lennon camp re-released “Rock and Roll”, a practically soulless collection of rockabilly and so-called “race music” covers.

“Acoustic” is by leaps and bounds more interesting, with its broken-radio production values and minor degree of fortuitous sloppiness. The Lennon “favorites” that one might expect on such a record are rather well-represented here. These include “Working Class Hero” (which begins with John barking cantankerously at Yoko, “OK, I’ll try it, OK?”), “Love,” “Look at Me,” “Watching the Wheels,” and a live version of “Imagine.”

But also included are several haunting curveballs, such as the brief, gut-wrenching take of “My Mummy’s Dead”, the briefer, descanted “Woman is the Nigger of the World”, and the disembodied “It’s Real.”

The quality of the recordings ranges from low to practically worthless. The guitar bombinates, grumbles, blows noise out of the speakers, or sounds as if the instrument were recorded through a microphone resting in a bathtub chez Lennon. And yet Lennon’s voice resounds with striking momentum and directness, then descends to his cultivated, understated crooning, then rises again.

Over the course of the album, he goes through bombast, fury, uncertainty, ardor, solicitude and resolve. On “Well Well Well” he crows and growls a joke of a blues ballad (“I took my love on out to dinner / So she could get a bite to eat / She was a-looking so much thinner / She looked so beautiful I could eat”). On “Look At Me,” his voice nearly breaks at several points and then does. And on “Cold Turkey”, the notes he sings tremble so cuttingly it is almost difficult to listen to it.

The ingenuity and expertise with which Lennon crafted his songs is the source of the album’s true wonder. Stripped alarmingly to their skeletal essentials, the songs remain definite and charged with a rare integrity. Even the unrealized fragments of which the album is partly composed contain some moments so admirable, calamitous, or stingingly beautiful, as to merit repeated returns. This to say nothing of a fully-formed and astonishing song like “Imagine,” which, played live and alone, seems enough to open the skies and bring quiet thunder down upon its listeners.

There is, however, the issue of this album’s existence in the first place. Many of the tracks can be found in more complete forms on already-released albums, and the bare presentation is, to some extent, frustrating. Where, for example, is “Jealous Guy,” a track one could imagine getting stellar acoustic treatment?

But these are paltry concerns given how simply strong the tracks on the album are, not to mention the considerable thrill of finding the chords to each of the songs contained in the liner notes.

The threadbare character of these bizarre and immediate recordings ultimately brings out the stark, never-duplicated force of Lennon’s songs, with all of their outrage, love and lasting efficacy.