my parents weren't really around my scene. They had their own tunes to listen to, and didn't really care what I listened to. Playing in a swing band back in the day helped to blur the generational lines, but my mom was a rock'n'roller (a la Happy Days) and a Beatles freak too.
My dad would retreat into his Wagnerian symphonies for respite, but he also sang in an Ink Spots (
http://inkspots.ca/ ) cover group called the Pink Spots as well as the church choir.
I do recall freaking out my mom once as a teenager, by jacking up the stereo system with Zeppelin's Whole Lotta Love, at the scream. But other than that, no reaction.
As for myself, my kids are self regulating. After a brief, but embarrasing foray into boy bands and the Spice Girls, they have settled down, and are now staunch supporters of classic rock, new rock and its variations (punk, thrash, ballads) and are developing a taste for blues work.
They are the ones that have put their feet down, and refuse hip hop (anything even though i try to engage them into the pre gangsta sensibilities of root reggae, ska, rap etc) .
If it comes down to a ban, the only thing that I have objected to was purchasing a Cradle of Filth album for my 16 yr old as it had misogynist lyrics.