Mainstream Nashville country is so helplessly in thrall to songwriting convention that it’s hard to tell decent singers from generic one-hat wonders. Brad Paisley tends to sidle up to a tune, and that relaxed delivery keeps his love songs from becoming unduly sentimental and his funny stuff from elbowing you in the ribs. The title track of his 2003 disc, Mud on the Tires (Arista), for instance, is an invitation to an off-road romp that’s sung so casually it takes several listens to hook you. Paisley’s restraint proves disastrous on the first single from the album, “Celebrity”–essentially a toothless, down-home rewrite of Good Charlotte’s “Lifestyles of the Rich and Famous.” But few other men in mainstream country could make the patronizing “Little Moments,” a series of anecdotes about how cute his honey is when she embarrasses herself, feel so indelibly sweet.

Terri Clark’s kiss-offs, like her 1995 hit, “Better Things to Do,” never sound just cutely spunky or harshly butch–credit her hearty, personable alto. But on more recent tracks from her 2004 compilation, Greatest Hits 1994-2004 (Mercury Nashville), she’s found wiser and more productive uses for the comfortable warmth in her voice: “Girls Lie Too,” about bending the truth to protect the male ego, and “I Just Wanna Be Mad,” about not wanting to make up right away after a tiff, offer lessons in asserting yourself without saying good-bye.

Reba McEntire headlines, Paisley plays second, and Clark opens. Sat 5/21, 7 PM, Tweeter Center, I-80 and Harlem, Tinley Park, 708-614-1616 or 312-559-1212, $29-$53.75. All ages.