Though he didn't have to, William Homans III, born 70 years ago in upper-class Boston, has lived a life that befits a bluesman: soldier, farmer, truck driver and practitioner of other earthbound forms of employment. He's also worked as newspaper reporter and political activist. He's described here as "Mensa-smart."

The "Watermelon" in the name derives from a stint as a watermelon grower at one time in a colorfully varied career. But what brings him into this space is his recording history which began in 1973 and since then has consisted largely of blues albums. He practices the genre on harmonica and electrified slide-resonator guitar, the latter in particular bestowing a hard-core, rooted feeling on his performances.

There is also his profound knowledge not only of blues itself but of the musics that rubbed shoulders with it in its formative years. These include ballads, folk songs and field hollers. Slim understands, for example, that "Smokestack Lightning" is not in fact a Howlin' Wolf creation (notwithstanding the composer credit) but a traditional number Wolf reworked from Charlie Patton, with whom he rambled in Mississippi in the early 1930s. Most of its lyrics were floating in the air when Patton grabbed them. Slim grabs some more, including words from an ancient Child ballad that migrated into African-American song as "Cabbage Head," often known in British and Irish tradition as "Seven Nights Drunk." Note, too, the line about "the man with the derby on," passing through from "Poor Howard" and elsewhere. "Lightning" is impossible not to love, no doubt explaining why it's so often recorded. Slim fashions a welcome and distinctive version.

Sharing the stage on Church of the Blues are top-flight veterans like Joe Louis Walker, Bob Margolis, Albert Castiglia and Sherman Holmes of the Holmes Brothers, underscoring the point that Slim is respected in all the right quarters. They showcase a tough, lived-in sound that clearly comes from somewhere but also establishes its own residence. Slim and associates satisfyingly cover classics like "61 Highway Blues" (Mississippi Fred McDowell) and "Gypsy Woman" (Muddy Waters). Some of Slim's originals speak to topical concerns, such as the environmentally focused "The Water Song" and the anti-fascist "Charlottesville (Blues for My Nation)."

No one will complain that Slim is less than a fiercely compelling vocalist, in contrast to many white blues musicians who can't deliver those essential goods whatever their other talents. If your tastes run to the hard stuff, Church is well worth attending. However....

At moments Slim's sentiments turn to the messianic (the only adjective that comes to mind) in the mostly unaccompanied "Holler #4." And I wish he had resisted the temptation either to write or to record the concluding number, "Halloween Mama," which is cruel even if -- I guess -- meant to be funny.