The Concerto was composed in 1968 for the virtuoso bass player Gary Karr, and it is a piece that explores a wide range of musical possibilities of the bass string instrument with chamber orchestra. It is demanding in a wide variety of techniques. The Concerto offers an introduction and coda, which are similar; there are seven movements, which are continuous, with the fourth movement as the longest and the improvisatory center of the entire composition. The other movements are so structured that the first and seventh have elements in common, the second and sixth, and similarly the third and fifth. The composer has achieved an instrumental variety within this frame by scoring for the full ensemble, or for the strings, or for the wind group—woodwind or brass. Altogether, its arched structure creates a varied and engaging musical realization.
The Concerto’s introduction is scored for the full ensemble; it is coloristic, but there is clear evidence that the solo instrument will have a demanding role. The first movement is scored for strings at a moderate tempo; it begins and closes softly, and the solo instrument takes a leading, even dominating, position in the musical action. The second movement is scored for woodwind and brass with the solo instrument and there are marked rhythmic figures; a solo cadenza is used to lead into the third movement. The tempo changes to adagio for the third movement, which is scored for strings; colorful sonorities are created by a variety of string techniques in which carefully gauged dynamics support the florid action of the solo instrument.
The fourth movement of the Concerto is the structural center of the work; it is scored for the ensemble, and an interesting feature, unique to this movement, is the use of “clock time,” that is, the various musical events are controlled by the number of seconds assigned to each—there is not the usual metrical barring and the music, which emphasizes coloristic elements, is metrically free.
The fifth movement of the Concerto follows without a pause; it is marked andante sostenuto and is scored for the winds, although strings appear briefly (its counterpart, movement three, was scored for strings); a more extensive solo cadenza joins the fifth on to the sixth movement.
The sixth movement is scored for strings (its counterpart, the second movement, was scored for winds), and the music provides colorful and constantly shifting densities and dynamic levels for the motion of the solo instrument. The seventh movement, quite short, recalls the second movement, and a coda brings back elements from the introduction.