by Richard S. GinellHaving let eight years pass since his last A&M album, Quincy Jones made his debut on his own label with his most extravagant, most star-studded, most brilliantly sequenced pop album to date -- which could have only been assembled by the man who put together "We Are the World." Jones was one of the first establishment musicians to embrace rap, and one of the first to link rap with his jazz heritage; it's hard not to be moved by the likes of Miles Davis, Dizzy Gillespie, James Moody, Ella Fitzgerald, Joe Zawinul, Sarah Vaughan, and George Benson electronically appearing on "Birdland" and trading brief licks with the likes of Kool Moe Dee and Big Daddy Kane on "Jazz Corner of the World." Later, jazz buffs would vilify Jones for not taking fuller advantage of this one-time constellation of jazz stars, but at the time, it seemed like a marvelous dialogue between the old and the new. Of course, as he well knew, celebrating jazz history is not the surest route to a blockbuster hit record, so there are plenty of radio-friendly urban pop productions here, with Herbie Hancock and George Duke on keyboards, and Siedah Garrett and 12-year-old Tevin Campbell on vocals. Despite the presence of an enthused Ray Charles, Chaka Khan, and the Brothers Johnson, the overly busy techno remake of "I'll Be Good to You" doesn't cut the Johnsons' original -- nor does "Tomorrow." Ultimately the most popular track would be the most tedious for the jazz listener, "The Secret Garden," with a parade of smooth soul balladeers producing make-out music at length. Yet Back on the Block remains a strikingly durable piece of entertainment, and in hindsight, a poignant signpost of the changing of the guard.