Sweet vocal jazz for the post-club generation that could have been made decades ago, Koop's debut album finely treads the line between the hipster posturing and lounge perfection that is the specialty of acid jazz radio guru Gilles Peterson.

Lush orchestration and hard bop rhythms make Waltz for Koop a pleasing sensation, but it is the rotating cast of vocalists that gives the album a strength beyond kvetch.

Newcomers Cecilia Stalin and Yukimi Nagano both follow the fluttering vocal lineage of Astrud Gilberto on two songs each.

The ladies perform effortlessly next to songs featuring certified vocal greats Earl Zinger and Terry Callier, each of whom wrote the lyrics to their respective numbers, "Modal Mile" and "In a Heartbeat." Callier's turn is the highlight of the album, with Koop augmenting the master's voice and their own retro melodies with subtly modern sounds, creating a fusion that remains true to the traditional form while staking their own 21st century musical claim.

Though Koop occasionally steps into pretension (the album contains several unnecessary vocal interludes taken from old jazz programs), Waltz for Koop is one of those rare albums that succeeds in paying homage to the artist's heroes without sounding like watered-down versions of said forerunners.

Put any of this album's songs on a mix tape next to a classic by Elis Regina or Chet Baker, and see if it doesn't fit together.