One of the first masters of the walking bass, his association with Basie goes back to the 1920s. He possessed a superb sense of timing that helped promote the bass to its role as principal timekeeper in the band. Which musicians fits this description?

Walter Page.

Explanation:

Walter Page was born on 9th February 1900. He was considered the finest bassist of the 1920s. The 1920s was the era of when big band swing music was voguish.

Walter never performed solo but still, he managed to be recognized by everyone. He had performed in Count Basie's unbeatable rhythm section. After which he gained popularity. He died at the age of 57.

So, the correct answer is Walter Page.