In the twilight years of his storied career, Frank Sinatra recorded a stunning rendition of “Send in the Clowns”, the bitter love ballad from A Little Night Music that marked Stephen Sondheim’s only appearance on the Billboard charts. “Send in the Clowns” is a beautiful, heartbreaking song in its own right, but it’s the dry, aching weariness in the aging Sinatra’s voice that makes his version transcendent. Sure, his voice isn’t as sparkling or smooth or technically proficient as it was in his heyday, but there’s something about hearing a man in his golden years tackling a song that lends it an extra element of gravitas, as if every syllable he sounds out is absolutely indispensable.

That’s what makes the tracks compiled on The Best of the Improv Recordings, the latest release from Tony Bennett, so special. The album takes its title from Improv Records, the short-lived label co-founded by Bennett during the mid-1970s. Although the label suffered from its lack of exposure and soon folded, some of Bennett’s finest music was released through Improv, including two excellent full-length collaborations with jazz pianist Bill Evans. The Best of the Improv Recordings amasses 16 songs recorded by Bennett during his time at Improv, a time when his estimable skills as a jazz singer may have reached their peak.

At the start of his career, Tony Bennett deliberately stuck to crooning in an effort to avoid comparison to Sinatra (who at the time was more known for his work with big bands). Aside from an energetic live recording of “I Left My Heart in San Francisco” that closes the album, he plays to those strengths here. Bennett’s voice is craggy, like Nat King Cole with a bit more muscle. He handles the come-hither baritone range with ease, as on his winking rendition of “My Romance”. But it’s equally impressive to hear him belting out tenor notes—listen to the way his laconic, tossed-off phrasing on “Make Someone Happy” gives way to chesty, full-bodied pleading in the chorus. This is the sound of an all-time great whose considerable talents continued to grow with age, and it’s a pleasure to listen to what he can do with a song at 50.

Conversations about standards singers usually begin and end with the quality of the voice, but what struck me most about The Best of the Improv Recordings upon first listen was the remarkable sonic unity of the album, especially considering it’s a compilation. On most best-of albums, an artist is compelled to cobble together an uneven amalgam of “greatest hits” with little to no regard for structure or flow. Here, though, Bennett takes three distinct bodies of work and flits between them comfortably and cohesively. Whether he’s backed by a lush orchestral arrangement, floating atop Evans’ piano, or mellowing out alongside the dreamy, acoustic guitar-flecked swing of the Ruby Braff-George Barnes Quartet, Bennett sounds relaxed, wistful, and maybe a little resigned. The entire affair is remarkably subtle and understated, achieving pathos without ever really veering into melodrama, and part of that is thanks to the album’s stellar organization; for instance, “Reflections”, which could come off as overwrought schmaltz as a standalone piece, is an unexpected gem when it’s heard right after the sparseness of “You Must Believe in Spring”.

Full of warm, cozy moments and devoid of gimmicks and missteps, The Best of the Improv Recordings more than does justice to a lesser-known period of Bennett’s career. In light of Bennett’s resurgence in the 1990s and 2000s, especially his 2006 Duets album and its upcoming sequel, The Best of the Improv Recordings highlights a more workmanlike Tony Bennett, one who didn’t have the cachet to augment himself with Elton John, or pitch correction, or a major release. Instead, he pared things down, took chances, and sang the music he loved at a time when it seemed no one cared to hear it.