But with the original remaining in print, Mr. Crane and the mastering engineer Adam Gonsalves had more leeway to experiment with the sound of the reissue, which they beefed up, using new technology, while removing excess noise for additional sonic clarity. “It started to feel like we were lifting the veil off,” Mr. Crane said.

For the bonus material — “dessert after dinner,” Mr. Crane said — he selected five live tracks from the Yo Yo a Go Go festival in Olympia, Wash., in 1997. “They really demonstrate how adept he was live as a guitarist — the fingerpicking, flat-picking and different techniques,” he said.

The new collection also includes a previously unheard studio rendition of the song “I Figured You Out”; a new version of “I Don’t Think I’m Ever Gonna Figure It Out,” the B side to the 1996 “Either/Or” single “Speed Trials”; a short and playful keyboard take on “New Monkey,” from “New Moon”; and an alternate recording of “Bottle Up and Explode!,” from the 1998 album “XO,” with completely different lyrics.

Mr. Crane said he hoped that for fans of Mr. Smith, the touched-up album and its revealing surrounding artifacts would reward the kind of close listening associated with canonical songwriters like Leonard Cohen, Nick Drake and John Lennon.

“You want to keep going deeper: What are they trying to tell me? What are they saying to the world?” Mr. Crane said. “Elliott was that good.”