Tom Jones is one of the most popular vocalists to emerge from the British Invasion. From the mid-'60s on, Jones has sung nearly every form of popular music -- from pop, rock, show tunes, and country to dance, techno, and more -- while his vocal style, a full-throated, robust baritone with little regard for nuance or subtlety, remained a swaggering constant. Mid-'60s songs like "It's Not Unusual" and "What's New Pussycat" registered on the charts, as did inimitable readings of country classics such as "Green, Green Grass of Home" later in the decade. As his career rolled along,...