There have been only five notable solo double-bass virtuosos in the past two-and-a-half centuries -- remarkable for an instrument developed before 1600 and refined ever since. Gary Karr is the most recent and widely famous of these rare players, virtually the Yo-Yo Ma of the cello's big brother. Domenico Dragonetti (1776-1846) came first, playing an instrument built by Amati in 1611. Giovanni Bottesini (1821-1889) followed, after him Franz Simandl (1841-1912), and then Sergey Koussevitzky (1874-1951), who played the 1611 Amati until he traded his bow for a baton in 1908. In 1924, Koussevitzky moved from a post-Russian base-camp at Paris to Boston, where he conducted one of the three greatest U.S. orchestras until his retirement in 1949 -- eight years after Karr's birth into a family that had been playing the double-bass for seven generations. Karr's paternal grandfather, father, an uncle, two cousins, and he (starting at age nine) played concurrently in Los Angeles-area orchestras until Gary entered UCLA, where he studied briefly with Herman Reinshagen before transferring to Northwestern University for study with Warren Benfield, then to The Juilliard School where Stuart Sankey became his principally credited mentor (he studied on the side, however, with mezzo-soprano Jennie Tourel, and cellists Gabor Rejto, Leonard Rose, and Zara Nelsova). He made his professional debut in 1961 with Thor Johnson (then Director of Orchestral Activities at NU after 11 years in Cincinnati) and the touring Chicago Little Symphony. Leonard Bernstein's Young People's Concerts with the NY Philharmonic in 1962 were his breakthrough, however -- the same year he made his solo recital debut in Carnegie Hall. After that concert, Koussevitzky's widow, who had attended, phoned him and made him a gift of her late husband's 1611 Amati. He played the historic instrument exclusively until recently, when luthier James Harn built a new one for him "of remarkable craftsmanship, beautiful wood, and superior power even to the Amati." But he still records on the 1611 Amati, and performed most of his concerts on it before officially retiring from the stage five months before his 60th birthday -- during the June 2001 convention at Indianapolis of the International Society of Bassists (which Karr founded in 1967). As a worldwide performer and TV personality, as a teacher for more than half of his public lifetime (including a videotape called BASSically Karr), and as the author of three textbooks on double-bass history and technique, Karr has been an indefatigable champion. In addition to master classes wherever he has played, he presides for four weeks annually at Karr Kamp, a summer school on the University of Victoria campus in British Columbia, where he makes his home. He established an eponymous Foundation in 1983 to preserve a collection of fine instruments for use without cost by gifted young musicians. Furthermore, he has commissioned more than 50 works, both concertos and solo concert pieces, from composers including Paul Ramsier, Hans Werner Henze, John Downey, Gunther Schuller, Lalo Schifrin, and Robert Rodriguez. Three things have characterized Karr's career beyond the achievements listed above. One is a career-long interest in children -- their pleasure and growth as listeners. Another is the sense of humor typified by puns in his promotional materials, and some stand-up comedy during certain kinds of performances. The third is his musical ecumenism: he has been as natural playing Christmas melodies and non-classical music (a CD of spirituals and Stephen Foster, for example) as he is in re-creating Bach's Cello Suites.