The superb 2016 six-disc John Coltrane box set The Atlantic Years: In Mono brings together most of the legendary jazz musician's Atlantic albums into one package, restored to their original mono sound. Beginning in 1959, Coltrane's Atlantic years were a transformative time for the saxophonist, during which he furthered his modal explorations and began incorporating aspects of the avant-garde, a vital combination that he would later bring to its pinnacle on his 1965 Impulse! classic, A Love Supreme. Included here are the landmark albums Giant Steps (1960), Bags & Trane (1959) with vibraphonist Milt Jackson, Olé Coltrane (1961) featuring trumpeter Freddie Hubbard, Plays the Blues (1960), and Coltrane's collaboration with maverick pocket trumpeter Don Cherry, The Avant-Garde (1966). Also included is a 32-page book featuring photos by Lee Friedlander and liner notes by writer Ashley Kahn. Sadly, the mono masters of Coltrane's other Atlantic albums My Favorite Things (1961), Coltrane Jazz (1961), and Coltrane's Sound (1964) were destroyed in a fire and therefore could not be included in this set. Also, as these albums are intentionally presented as they were on the original LPs, they do not include any of the alternate takes that have been issued elsewhere. Despite these omissions, The Atlantic Years: In Mono works as a succinct display of the core of Coltrane's Atlantic years and as a mono companion to the previous Atlantic Coltrane set, 1995's The Heavyweight Champion: The Complete Atlantic Recordings. The primary reason to investigate this box is to hear the recordings in their original mono production, an aspect that some listeners will prefer, some will dislike, and yet others won't care about either way. Nonetheless, there is an audible contrast between the way the mono versions sound and the way the later, and perhaps more readily accepted, stereo versions sound. Gone is the attempt to separate the musicians and place them in different speakers. Instead, we get a cohesive, single-microphone effect that some think better represents the way albums were recorded in the '60s. At the very least, this is how most people first heard these albums and it's fascinating to compare them to their stereo versions. Indeed, rather than imparting stereo's effect of feeling as if you are sitting at Coltrane's feet in the studio (admittedly a cool thing), the mono versions offer their own earthy, natural, in-room sound that is perhaps warmer and more compact, allowing you to get a better handle on the overall group's cohesiveness. It's a sound that works especially well on Coltrane's iconic ballad "Naima," where his plaintive saxophone moan, framed by pianist Wynton Kelly's delicate harmonic bed, is softer, more immediate, and perhaps even more poignant-sounding than on the stereo version. Ultimately, given the important nature of Coltrane's recordings and the historic accuracy achieved here, The Atlantic Years: In Mono is a more than welcome addition to Coltrane's archive.