While I am not a musician, this topic is of great interest to me. In my view, New Jack Swing (as an era/movement) and as a style of music never really received a decent burial. It's because of that (in my opinion) that there is such a sense of "huh?" surrounding New Jack. Most people are familiar with the genre's key artists (i.e. Keith Sweat, Al B. Sure! and Guy) but are *not* familiar with the label "New Jack Swing" and what that means.
As a style of music, producer/musician Bernard Belle (Teddy Riley collaborator too) talks about it here:
As an era, you can visit Njs4ever.com for a primer. In my humble view, one of the best slices of the New Jack Swing sound is "I Wanna Get With U" by Guy from the 1990 Future album. The tamborine sound specifically is what I'm referring to -- the way it is shaken in syncopation with the rest of the song. This rhythmic element can be found in all the hottest New Jack cuts of the day: "My Preogrative" by Bobby Brown, "I Want Her" by Keith Sweat, and "Just Got Paid" by Johnny Kemp.
In my view, the *true* New Jack music enjoyed its heyday between 1987 and 1992, ending around the summer of 1992. By then, the music changed a bit (in reaction to gangsta rap) and acquired a less accessible, harder edge (compare the sunny "Every Little Step" to the more aggressive "Humpin Around" for example).
I'm glad someone brought this up. Because of the silence surrounding the demise of New Jack Swing, the style was able to be resurrected and adapted by the Cheiron studios in Stockholm Sweden, and became a billion-dollar industry thanks to their pop success with Britney Spears, NSync (who remade "Just Got Paid"), The Backstreet Boys, et al...