No pantheon of guitarists is complete without Robert Johnson and Jimi Hendrix, the first as a seminal bluesman, the second as the player who took blues into sonic territory few guitarists had even glimpsed before. Both players’ ouevres have been mined for all they’re worth. Hendrix bootlegs and outtakes have been around for years, and Johnson’s small body of recordings has seen the light of day before. This year Legacy added to the substantial offerings of both players with new box sets, both worthwhile on their own terms if not totally new.

Robert Johnson’s The Centennial Collection collects the bluesman’s 1930s studio work, complete with alternate takes. What’s new here is only the mastering, though with recordings this old, a new master can be revelatory. In this case, the scratchy old 78 feel of past collections is replaced by a clarity that makes listening a different experience.

The improvement is subtle but effective: Johnson sounds more present and real than he ever has. The details of his stellar guitar playing are well defined, and it’s easy to hear why it was, according to legend, the result of a deal with the devil (“down at the crossroads”). For that alone, it’s a set worth picking up. Johnson did remarkable things with his guitar, weaving rhythm and melody in an exuberant sophistication, and interacting with his own vocals in a fashion that’s more commentary than mere accompaniment.

The rest of the set is interesting, if not particularly groundbreaking—it consists of other blues recordings of the era, and a DVD feature about Johnson.

Three decades after Johnson’s 1938 death (allegedly the result of poisoned whiskey), Jimi Hendrix’ star was in the ascendant. Hendrix was well aware of Johnson, and in his hands, the idea of guitar as something more akin to orchestra than autoharp reached its logical conclusion. Though Hendrix is known for his psychedelic sound excursions, the bedrock of his playing was always the blues. In the new set (also from Legacy) Winterland, fans get something of a learning experience. A set of songs from Hendrix’ 1968 concerts at San Francisco’s Winterland first hit vinyl in the late 1980s, but this box set goes well beyond those selections to offer audio from three nights of concerts.

The set lists were quite similar on all three nights, though each offers something unique. It’s more or less like having three versions of the original Live at Winterland release. It’s also extraordinarily illuminating to take any of the tracks that got repeat play and listen to each night’s version.

Hendrix played “Lover Man” all three nights, and the three takes differ in some large ways. The lengths vary, and Hendrix’ solo excursions reveal a player inspired by the moment to try very different things with the same material. Unlike many rock guitarists, Hendrix never quite seems to play the same solo twice, taking his melodies into whatever territory strikes him. Similar structures prevail, but within them, all sorts of textures and flights of melody arrive. Few players have approached Hendrix’ mastery of his instrument—there are no missteps, no clanging notes, and his improvising feels like an amplification of something inherent to the music that he’s exploring with as much expectation as his audience.

The two releases bookend single-guitar blues, offering the stylings of an early acoustic master and the mind-blowing explorations of the electric guitar’s most eloquent spokesman.