The mother often represents morality and good intentions—which is both good and bad for portrayals of women in music.
Miranda Lambert's most recent single, "Mama's Broken Heart," lurches between a sparse, echoey, hiccupping lope and a rock-punk wailing shriek. The bipolar dynamics mirror the central conversation of the song, which is not between lover and lover, but between daughter and mother, the second advising restraint following hearbreak ("fix your makeup, girl, it's just a breakup, girl/hide your crazy and start acting like a lady") and the first enthusiastically embracing her self-parodic hyperbolic Shakespearean despair ("I cut my bangs with some rusty kitchen scissors/I screamed his name till the neighbors called the cops.")
Lambert's mama, in other words, performs the same function as many a mama in country music—she's the voice of reason and social morality ("Word got around to the barflies and the Baptists/My mama's phone started ringin' off the hook") against which the singer gets to rebel. Examples abound. There's Johnny Cash's brutal, stripped-down 1958 single "Don't Take Your Guns To Town," in which Billy Joe ignores his mom's warning and ends up dead on a barroom floor. There's Merle Haggard's 1968, "Mama Tried," where the shimmering Bakersfield guitar rolls on irresistibly out of mama's arms, onto the rails, and into that prison cell. "That leaves only me to blame, cause mama tried." And of course there's Waylon and Willie's self-mythologizing "Mamas Don't Let Your Babies Grow Up to Be Cowboys," which straddles the line between joking sincerity and sincere joking as it describes the mama-alienating aspects of the cowboy life ("he ain't wrong he's just different/but his pride won't let him/do things to make you think he's right") Those mama-alienating aspects, of course, being the same things which make the cowboy life attractive.
Country's obsession with mamas is part and parcel of its obsession with tradition. It's one of the many ways that the music evokes and points to the rural past which it both constantly idolizes and constantly (though sometimes surreptitiously) celebrates its liberation from. Mama, then, becomes a convenient trope; a way to declare one's love for that old-time morality while emphasizing one's own tragic/sexy/cool/funny independence from it.
The gendered connotations are hard to miss. Mothers, after all, mean hearth and home and long-suffering love for their rebellious children. Those children are quintessentially boys—which doesn't mean women can't take up the script, but does mean that when they do so, things tend to change around a bit. For instance, in the Forester Sisters 1986 single "Mama's Never Seen Those Eyes," the daughter isn't rebelling by taking her guns to town or being a dangerous guy—she's rebelling by falling for a dangerous guy (with, as the title says, very pretty eyes). And, again, in Lambert's single, the daughter doesn't shoot anybody or become a lonely dangerous sexy cowboy—she just gets upset because her man dumped her. The interest in tradition that makes mama worth singing about, then, also tends to result in a fairly stereotypical take on gender roles, with guys roving and rambling and causing trouble, and women either watching them cause the trouble and/or having the trouble done to them.
On the one hand, this is obviously fairly limiting. On the other hand, though, it's not like the pop world outside country necessarily offers a huge range of options for women, either. In pop, women can be sex kittens, they can be sexually aggressive bad girls, they can be sexy waifs...or, yeah, they can be sex kittens. Anything they want, in short, as long as it has sex in it.
Country's willingness to consider women as mothers in addition to considering them as (sexually available) daughters isn't always liberating, by any means. But it is, or at least can be, an alternative that isn't generally explored or exploited in other parts of the pop landscape. At the least, this means that country is sometimes able to see mothers not just as stock characters, but as people whose experiences may in themselves be worth singing about—as in Loretta Lynn's glorious 1971 ode for harassed parents, "One's on the Way."
That song explicitly distances its narrator from the "girls in New York City [who] all march for women's lib." But the ability to see mothers as human beings also makes it possible for country on occasion to have something that starts to look like an honest-to-God feminist vision. "To Daddy," a hit for Emmylou Harris in 1970, for example, about the emotional aridity and monotony of a stay-at-home mother's life, sure sounds like songwriter Dolly Parton was channeling Betty Friedan. In any case, it's hard to imagine Friedan wouldn't approve of the conclusion.
She said the kids are older now they don't need me very much
And I've gone in search of love I need so badly
I have needed you so long but I just can't keep holding on
She never meant to come back home
If she did she never did say so to daddy
Goodbye to daddy
On that last line, Emmylou's voice lifts up, echoing those lonesome train whistles that all those ramblers hear when they leave mama behind. Only this once, mama gets to take that train and leave tradition behind, riding for another country.