Soul-Jazz is an extension of the jazz idiom that incorporates Soul and Rhythm and Blues in it’s sound, yet is still grounded in the unified inprovisational structure that makes jazz. This style was made popular by a variety of musicians in the late ’50’s and early 60’s by artists like Grant Green, Jack McDuff, Richard ‘Groove’ Holmes, Lou Donaldson, Jimmy Smith, and Horace Silver, whose funky piano style is credited with planting the seeds of Soul-Jazz. It was Jimmy Smith who popularized the Soul-Jazz organ combo (usually tenor sax, guitar, drums, stand up bass) in the late 50’s, allowing other groove-oriented organists to become stars in their own right (including the aforementioned McDuff and Holmes, Shirley Scott, and Jimmy McGriff). Guitarists with groove oriented sounds also became leaders in the soul-jazz field, with Green, Kenny Burrell, and George Benson leading the list. In the mid to late 60’s a more thumping, danceable version of soul-jazz emerged–jazz-funk.
Here’s AMG’s (All Music Guide, http://allmusic.com/) take on Jazz-Funk:
In its earliest incarnation during the mid-’60s, Jazz-Funk was an earthy amalgamation of jazz and funky Southern soul, also heavily influenced by the proto-funk innovations of Sly & the Family Stone. In that respect, it was fairly similar to soul-jazz, but where soul-jazz was often content to lay back in the groove, jazz-funk drove forward with a stronger, more pronounced backbeat, as well as a more explicit devotion to the Stax/Volt brand of soul music (sometimes reflected in cover versions of popular soul hits). Many early jazz-funk artists were organists, like Lonnie Smith, Reuben Wilson, Charles Earland, and Jack McDuff (some of whom crossed freely between jazz-funk and soul-jazz); other key figures included saxophonist Eddie Harris and vibraphonist Roy Ayers. As the grittier strain of soul metamorphosed into funk during the early ’70s, and as fusion helped make funk rhythms a compelling way for some hard boppers to reconnect with their African-American audience, the crucial R&B component of jazz-funk shifted with the times. Artists like trumpeter Donald Byrd, flautist Bobbi Humphrey, and keyboardist Ronnie Foster crafted a sunny, breezy style by performing compositions which often simply resembled jazzy R&B, and drew from Philly soul as well as funk. Keyboardists like Herbie Hancock and Lonnie Liston Smith explored a spacier, more atmospheric brand of jazz-funk, while the artists on Creed Taylor’s CTI label (most prominently Freddie Hubbard) were wrapped in a shinier, more polished production. Fusion and jazz-funk shared many sensibilities during the early ’70s, but it’s important to realize that not all fusion was jazz-funk, and vice versa. Fusion could encompass a greater variety of moods and influences, whereas jazz-funk was always marked by its devotion to R&B, and maintained the upbeat, celebratory vibe of funk. Just as funk was eventually smoothed out into disco, jazz-funk melted into the smoother, more polished brand of crossover-oriented fusion that dominated the popular, more accessible side of jazz during the ’80s and ’90s. Because of its emphasis on danceable, funky grooves, jazz-funk became highly popular in the British underground music scene (where it was known as “rare groove”) when it was rediscovered during the mid- to late ’80s; an update version mixed with funk and hip-hop became known as acid jazz. For similar reasons, jazz-funk was also the style to which many American hip-hop artists turned when looking for ways to fuse jazz and rap; Roy Ayers, in particular, enjoyed a renaissance and reappraisal in both scenes. Plus, artists like Medeski, Martin & Wood helped revive the classic jazz-funk sound and bring it to newer, wider audiences in the ’90s.
Personally, I became very interested in soul music in my later teen years. I graduated to funk in my early 20’s. Then I became deeply interested in Jazz, so it was a natural progression for me to develop a fondness for soul-jazz and jazz-funk. I listen to every artist mentioned previously, but also enjoy listening to more obscure artists that may have only issued a few or one album. I especially enjoy recording on the Prestige label from the late ’60’s and early 70’s from artists such as Rusty Bryant, Charles Kynard, Melvin Sparks, and Bernard Purdie.
Other obscure favorites: