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.