Serious music fans in Louisville are all atwitter with the news that postmetal instrumental band Russian Circles will be appearing at The Vernon Club on  August 8. Lest you be confused, postmetal means that they play delicate passages in their music has well as extremely loud parts, in the manner of art-metal. (Classification gets a bit complicated these days.)   Suffice it to say that show is promoted by Terry Harper, who leans to the loud. Opening will be Marriages and Chelsea Wolfe, whose style has been described as a "specific brand of drone-metal-art-folk." Does that help? Tickets are $13.

--Paul Moffett