Jazz Pianist Keith Jarrett Jazz pianist Keith Jarrett. Called one of the greatest improvisers in the history of jazz, Jarrett was famous for his wildly passionate solo recitals. In 1996, Jarrett came down with a mysterious illness-- an interstitial bacterial parasite-- that caused him to stop performing for about two and a half years. Jarrett has started performing and recording again, but he still keeps a low public profile, so his condition will not worsen again. His newest CD, Whisper Not (Universal Classics), will be released next month. His other recent CD, Melody at Night, With You, was a solo album Jarrett recorded at his home studio in rural New Jersey.