TORONTO -- Sarah Bratt's daughters may only be four and six, but they have a keen sense of the music they like, and are savvy enough to stream it themselves.

Invariably, the rotation includes modern-day pop hits by the likes of Cardi B, Maroon 5 and Bruno Mars, but listening to those songs without supervision is a treacherous proposition for Bratt. She's on constant alert to nix inappropriate material, whether it appears online or over the airwaves.

"The radio sometimes plays stuff that's sexually explicit or there are curse words in the songs," notes the 38-year-old Vancouver mom, who also has a 15-year-old son.

"The F word seems to be more allowed now, even on regular television than it was when we were younger, and certain words that were completely forbidden before are for sure more mainstream now."

Bratt gets around those hazards by restricting the girls to YouTube Kids, setting up kid-friendly playlists on their Apple Music account and stocking up on CDs by "clean" pint-sized cover bands including the Mini Pop Kids and Kidz Bop. They also like Fred Penner, Rick Scott and Jojo Siwa.

"When you have the Mini Pops on you don't have to worry about that -- you're not all of a sudden (saying), 'Oh my goodness! Earmuffs!"' she laughs, recalling an expletive-laden track that recently came up while scrolling through radio stations in the car.

If it seems like pop music has become more explicit, it's because it has, says industry watcher Dustin Rideout.

He credits the declining influence of traditional gatekeepers -- including radio and music television -- with allowing artists to push the envelope with more adult themes. Streaming services including Spotify and Apple Music allow listeners to filter out explicit songs, but things still slip through, and not all artists make family-friendly versions, says the chief strategy officer of the marketing firm McCann Toronto.

"There's always been for many decades a battle between artist and the establishment," says Rideout, suggesting some artists equate radio edits with the old guard.

"As more musicians and artists can control the trajectory and speed at which their careers grow, I think that's one aspect that's driving it."

In the meantime, consumers have more power than ever to filter the material they get, he says, positing that a growing appetite for clean tunes has fuelled the rise of squeaky-clean K-Pop.

Mini Pop Kids producer Samantha Kives believes there's a big gap in the market for the relatively wholesome fare that her tween stars first became known for in the '80s.

The kid-friendly group has stripped the kitschy outfits and heavy makeup that marked those early covers of songs by Madonna, Bananarama and Boy George.

Their latest album, "Mini Pop Kids 16," includes tweaked takes on Post Malone and Ariana Grande and court a tech-savvy generation weaned on streaming services and online videos.

"There's more of a need now for the Mini Pop Kids than there was even back then because as time has gone on, language has gotten more sexual, it's gotten more vulgar, it's gotten more offensive."

The group, which features young singers from across Canada, simultaneously taps into parents' nostalgia for the neon-hued original, she adds.

Kives is the daughter of Philip Kives, the Winnipeg-based pitch man who brought the U.K. group to Canada in the '80s with a series of successful album releases.

K-Tel International, the music production and licensing company, revived the Mini Pops with Canadian members in 2004, this time acknowledging evolving sensitivities to cultural and sexual taboos, says Kives.

"For us it's really, really important that we are presenting really good role models for the young kids that are listening to our songs and so we want our kids to look like they're relatable and they're wholesome," Kives says of today's performers, aged 9 to 13.

"We have not very much makeup, we don't show skin. They're kids and we want them to be kids."

Sales data suggests appetite for children's music in general is on the rise.

The children's genre saw 26 per cent gains to date over the same period last year when 468,000 units sold, according to Nielsen Music. Consumption jumped nine per cent the year before that, and 11 per cent the year before that.

The Mini Pops did especially well with their 13th collection in 2015, when it sold 35,000 albums. This year's two-CD release has sold 11,000, according to Nielsen data.

The group wraps a 40-date tour this Saturday in Toronto, and have plans to tour again in the fall, says Kives.

She suspects today's Mini Pop audience skews younger, with kids as young as three finding their videos online and showing up at concerts.

Rideout says his research suggests that's likely true, noting today's preschoolers and young grade-schoolers are a generation that has been using iPads since infancy and are increasingly likely to influence many of the family's entertainment choices.

Again, he points to social media influencers and online videos for fuelling that trend: "The way that people discover and music spreads is not through linear formats."

Still, Rideout doesn't discount the persuasive power that parents still wield in shepherding their kids' tastes in music.

"Nostalgia for nostalgia's sake rarely works and if it does it's a very quick flash in the pan. The Mini Pops as a brand kind of hits two things -- one yes, there is a nostalgia with the people that would be buying, would have consumed it at one time (but) what they're doing that's really smart is they're recontextualizing it to the desire of the consumer today," he says, noting that the resurgence addresses a problem for many consumers.

"I would argue the Mini Pops is poised to be significantly bigger than it was in its origination."