At Carnegie Hall the Preservation Hall Jazz Band showed how easily it could hop from era to era. It could work like a rhythm-and-blues horn section or a tightly arranged little big band if need be, but it could also switch back into the polyphonic glories of vintage New Orleans jazz, in which nearly every instrument seems to improvise around the tune at the same time.

The Nile Project is the performing side of an effort that also includes education in music and environmental issues, raising awareness of the entire Nile basin as an ecosystem. With such vibrant music, the good intentions were a bonus; the Nile Project was a superb example of what I call small-world music, of what happens to traditions in the information age.

Wynton Marsalis' skills have grown as fast as his ambition, and he is the most ambitious younger composer in Jazz.

Baikida Carroll, whose balance of bravada and tenderness, facility and understatement mark him as a player to be reckoned with.

Hearing Marilyn Crispell play solo piano is like monitoring an active volcano. She is one of a very few pianists who rise to the challenge of free jazz.

Booker T. Jones sounds more pithy and forceful than ever on “Potato Hole”…Mr. Jones still jabs terse, unhurried melodies that sound as if he knows the lyrics but would never tell. Where the M.G.’s suavely underplayed their aggression, the rockers’ multiple-guitar attack, with distortion and feedback, gives the music teeth.

At Carnegie Hall the Preservation Hall Jazz Band showed how easily it could hop from era to era. It could work like a rhythm-and-blues horn section or a tightly arranged little big band if need be, but it could also switch back into the polyphonic glories of vintage New Orleans jazz, in which nearly every instrument seems to improvise around the tune at the same time.