Charlie Haden, Thursday, August 3, at the Denver Botanic Gardens, has quietly had one of the most distinguished careers in the short history of jazz. As a key part of Ornette Coleman's most famous combo, he contributed the sonorous bass lines that held together The Shape of Jazz to Come, Change of the Century, Free Jazz and other works of genius from Coleman, whose shadow looms large over the art of improvisation in the second half of the twentieth century. Later, he oversaw (with Carla Bley) the Liberation Music Orchestra, which merged left-wing political dogmatism with flowing orchestral jazz that would have put a smile on Duke Ellington's face. And this spring, with nearly forty years of playing behind him, he released Steal Away, a collection of spirituals, hymns and folk songs that he and collaborator Hank Jones render with awesome gentleness and sensitivity. Haden, accompanied on this date by his associates in Quartet West (Ernie Watts, Alan Broadbent and Larence Marable), eschews showy effects for a moving musical profundity that does justice to the past even as it strides confidently into the future. Would that there were more like him.