Fourplay Foreplay...

I think they chose the band name for the purpose.
Listening to their music says it all.
I got the 24/96 download from HD tracks and very much enjoy it. Good Sunday morning jazz....
Great contemporary instrumental. Jazz it's not.
Their first 2-3 albums were truly nice to listen to, musically and sound wise. Perfect to put on after a nice dinner out with the wife, and an after dinner drink on the couch with some "snuggling".

They weren't pure "jazz" but they did put a bit more into it than the typical "smooth jazz" group does. Unfortunately, when Ritenour left they became sonic pablum.
I'd say their music is more towards pop than to any jazz, but certainly one of the best for "foreplay" regardless weather they've chosen name to be or not.
Agree that their debut album is the best.
I'm a fan of Fourplay as I am of Coltrane, Blakey, Horace Silver, Miles, the Crusaders, Chick Corea, Lee Ritenour, Larry Carlton, etc. Jazz music is an art of improvisation. I recommend you read the book "The History of Jazz" by Ted Gioia. Excellent. There are many types and styles of jazz music which have evolved over its rich history including Dixieland, Swing, Bop (Dizzy, Charlie Parker, Monk), Cool (Miles, Coltrane), Latin, Soul, Fusion (Hancock, Corea,) Smooth (Fourplay, Boney James), etc. To say one is not an art form within jazz music is not really 100% true. They're all forms of jazz music.