“Untouchable.” That’s how Vince Gill describes the playing of bluegrass fiddler Michael Cleveland in the inspiring documentary about the Grammy-nominated musician’s life, Flamekeeper: The Michael Cleveland Story. On his new album Tall Fiddler, Cleveland lives up to Gill’s lofty praise, showing off the verve, dexterity and intensity that have made him one of the most transfixing performers today — of any genre.