If you want to put an artist in the canon of greats, you have to make a truly strong case. Screamin’ and Hollerin’ the Blues: The Worlds of Charley Patton (Revenant) makes about the strongest case that’s ever been made for a relatively unknown musical figure. A Delta blues singer who had a couple of successful records in the late ’20s and early ’30s, Patton is remembered mostly as a footnote, a musician’s musician, a favorite among obsessive collectors of old 78s. ("High Water," on Bob Dylan’s recent Love and Theft, is a tribute to his merciless two-part blues "High Water Everywhere.")

This seven-CD boxed set is no footnote. The beautifully designed package includes every note Patton ever released under his own name (alternate takes are neatly concealed before Track #1 on two discs); everything he played on by other artists; recordings by other artists at which he might have been present; a disc of songs by his contemporaries that have some bearing on his own work; a disc of interviews conducted in the 1960s with people who knew him (he died of heart failure in 1934); a facsimile reproduction of guitarist John Fahey’s 1970 monograph on his life and music; a gigantic book with every piece of biographical, musicological, and discographical information there is about him, analyzed as far as is even vaguely reasonable; stickers reproducing the labels of every original Patton record, even handwritten labels from test pressings, . . . and a reproduction of the one extant photograph of him.

This is a man in full — everything there is left of a sharecropper’s son who made his living as an entertainer and rarely left the Mississippi Delta in his 43 years of life, with enough context that it makes some kind of sense. And the fact that there’s only that one photograph says something about how slim the historical record of Patton’s world is. Under the circumstances, the completist-and-then-some approach of Screamin’ and Hollerin’ is a great idea. It explains, more effectively than words alone could, what Patton had in common with his contemporaries and in what ways he was radically different. The experience of hearing his "Moon Going Down" is indeed deepened by the inclusion of Tommy Johnson’s "Maggie Campbell Blues" (the first recorded use of its melody), a couple of records by Patton’s accompanist, Willie Brown, and a note that compares the lyrical structure of "Moon" to Patton’s own "Future Blues."

This is, of course, assuming that you want to have the experience and then want to have it deepened. Patton’s music isn’t always instantly likable. Very few of his songs were compositions in the familiar sense; he seems to have plucked verses out of an enormous repository in real time, even when he was implying something like a story. (Fahey’s famous description of his lyrics: "Various unrelated portions of the universe are described at random.") His enunciation was legendarily indistinct — the near-total absence of consonants from his speech led his "Hammock Blues" to be released as "Hammer Blues." He had a couple of clever tricks, like making his guitar imitate a voice and complete a phrase for him, but the all-out crowd pleasing he was known for doesn’t show up much on record.

Still, there’s something richer going on in Patton’s best songs — a roiling surface that sucks you into profound mystery. That "worlds" in the title of the set is plural because he always seems to have one foot in our own world and one in a world that’s entirely his own. (Even his mangled roar sounds as if he were keeping part of his words to himself.) His playing implies more than the notes that are there; the language is half blues commonplaces and not-quite-remembered verses from other people’s songs, half offhand personal references. And everything he sings seems like an excerpt from some much larger song with dozens of streams of thought running through it. There is the sense about his recordings that he didn’t simply rehearse and perform songs; he was making his art in every waking moment, drawing it from the air and the culture around him, and he parceled it out in three-minute chunks for the recording machine. We can’t experience it as a whole, but we can see how the surviving pieces fit together.