Jim Hall turns 80 next month. The recent years have been rough on the master, but he can take consolation in the fact that he remains the premier jazz guitarist. Not to slight contemporaries ranging from Wes Montgomery to John McLaughlin, but no jazz plectrist has yet to match Hall's extraordinary touch, harmonic imagination, lyrical bent or economical approach. His sound is instantly recognizable and consistently beautiful. Equally munificent is his craving for new musical experiences. If ever there was a man who could safely luxuriate in his own comfort zone it's Hall, but something keeps pushing him to rattle the cage. His openness and generosity is clearly illustrated when he goes head-to-head with younger players who have been influenced by him. The stealthy Bill Frisell wears his Hall credentials more openly than the dashing Pat Metheny, but Hall himself takes both stylists in stride. It's the old man who makes the young bucks sweat.