A Windham Hill Jazz Collection 　　Keyboardist Doc Powell produced and played keyboards and composed most of the tunes on the CD titledDouble Scale, yet his name appears nowhere on the cover. Perhaps he's still under contract with another label. Whatever the case, this clearly Powell's project, although he takes a background roll throughout much of the disc. Each tune features a notable guest artist, such as pianist Bobby Lyle (on two tunes), Chuck Mangione, Joe Sample, Tom Scott, and Everette Harp. Most of the program should fit comfortably on the smooth jazz playlists, which means that it's highly listenable, has memorable melodies, and while not terribly far-reaching or challenging, is nevertheless very competently done. (Windham Hill Jazz 11425) 　　 　　After only a few hit projects establishing himself as one of the genre's most popular guitarists, it seems curious why Doc Powell would conceive and produce an all-star concept album like Double Scale rather than do another solo album which might further cement his stature. That said, this is a can't miss event in smooth jazz/urban funk circles, a fun-filled opportunity for those less initiated with the format to get acquainted with none other than Everette Harp, Bobby Lyle, Chuck Mangione, Joe Sample, and Tom Scott, all of whom Powell writes showcase tunes for. Powell is so intuitive at knowing their strengths that each tune would fit perfectly on the artist's own albums. Harp doubles his alto and tenor as he carries an in your face melody throughout the bouncy funk of "Locomotion," while on "Southern Winds," Powell lays down a gentler, easier flowing rhythmic foundation for Lyle to strut his elegant funk stuff. He takes the silky smooth approach to the extreme on Mangione's piece, the soundscape heavy, ambient "Miss T"; if you didn't know the famed flugelhornist's résumé, you might think he was inspired by the cool sounds of Chris Botti. The tune for Sample, "Jungle Walk," captures a similar easy percussion vibe, allowing Marcus Miller to build a dramatic bassline over which the pianist ranges from dark toned chords to those cheery high register melodies. Powell steps into the spotlight on the uptempo "Sassy," which features his sharp acoustic work and a breathy, synth-created vocal chorus.