Including the various bonuses floating about, Guilty Pleasure is twenty tracks of pure pop-rock at its finest that you really shouldn’t feel guilty for enjoying. Songs like the wonderfully-named Hot Mess, Masquerade, Delete You and the eponymous Guilty Pleasure will lodge themselves in your brain within a couple of listens and need Herculean levels of persuasion to coax them out again. Tisdale channels a Britney-Blackout lite on Crank It Up and Blame It On The Beat to winning effect; Acting Out, Overrated and Tell Me Lies are in the vein of Avril or Ashlee before they got too annoying whilst Erase & Rewind manages to be reminiscent of Katy Perry yet better than the majority of her album, without a whiff of Sapphic scandal in sight. Hair and Switch are cheesier than a platter of mouldering Roquefort yet substantially more delicious. Meanwhile, the Disney schmaltz that smattered her debut album is thankfully kept to a minimum – quality control ensures that even this balladry (the lush Me Without You and What If) is actually quite nice.

Tisdale might not have the vocal strength of a Clarkson, or even a Perry, yet she does have a distinctive tone that brims with character and charisma, rather like Tisdale herself (her Sharpay remains the mischievous knowing glee that anchors HSM). Guilty Pleasure will not change the world yet is all the better for knowing its boundaries. As a result, it’s frivolous fun that has not left my music player since its release.

And though the 23-year-old actress and singer wasn’t even born when Thriller came out, she told MTV News that Jackson was a big influence on her music and the work of her “HSM” castmates.

“I’ve loved Michael Jackson, his music, his music videos,” Tisdale said. “I mean, the man made music videos what they are today. So, I’ve always been inspired by him. I think he’s such a great dancer.

“It was definitely a shock,” she added of Jackson’s sudden passing. “It’s really hard when a celebrity dies out of nowhere, ’cause it’s very shocking … surreal.”

Tisdale was looking forward to seeing what Ortega and Jackson would be debuting on July 13, when Jackson was scheduled to kick off his This Is It tour. She said she and her “HSM” buddies were going to make the trek overseas to see it for themselves.

“We were all gonna go see him in London and go visit and watch the show,” she said, adding that the show would have also included dancers from the “HSM” movies. “We had a lot of our dancers in the production as well. I know they’re going through as really hard time as well. Hopefully, he’s in a better place now.”

“For the last few years everyone has thought of me as Sharpay,” the 23-year-old singer/actor says, referring to her blonde-and-bubbly character in Disney’s smash “High School Musical” films.

“So after I’d finished all the promotion for ‘High School Musical 3′ I dyed my hair back to its original color. I’d been a blonde for five years; Disney wanted us to be those characters. But the new songs I was working on felt edgier, sort of back to how I was before ‘High School Musical.’ I wanted to show people a side of me they haven’t seen before.”

Tisdale accomplishes that — well, sort of — on “Guilty Pleasure,” due July 28 from Warner Bros. Like her 2007 debut, “Headstrong” (which, according to Nielsen SoundScan, has sold 471,000 copies in the United States), the new 14-track set offers plenty of catchy choruses and lyrics about boys.

But with songwriting and production credits from “American Idol” judge Kara DioGuardi, among others, “Guilty Pleasure” is a more mature, guitar-driven outing than the dance-pop “Headstrong.” In the opener, “Acting Out,” she promises to “break these chains” over driving bubble-punk drums, while the lead single, “It’s Alright, It’s OK,” could be the younger sister of Pink’s “So What.”

“A lot of the songs on the album are about survival and staying strong,” says Tisdale, who co-wrote four cuts. “I really wanted it to be a statement and a reflection of what I’ve been through over the past year and how I’ve grown up.”

Warner Bros. senior VP of marketing David Grant says the first component of the label’s album rollout was revealing Tisdale’s new look with a relaunch of her Web site in March and the cover of Cosmopolitan’s April issue. “We wanted to create a conversation and then follow quickly with the music,” he says.

According to Grant, “High School Musical” fans have aged along with Tisdale, and they still constitute a significant portion of her audience. “But she’s taken it beyond that, too,” he says. For “Headstrong” the label targeted tweens; this time, “we’re definitely looking to teenage girls.”

Social-networking technology plays a central role in the label’s plans to reach that demographic. Tisdale is an especially avid Twitterer, with more than 750,000 followers.

“She’s very protective of it in terms of it sounding authentic,” according to Warner Bros. senior VP of new media Jeremy Welt. “There have been a couple of times where we’ve said to her, ‘Hey, why don’t you mention so-and-so?’ and she’s told us, ‘I wouldn’t say that.’” (What would she say? One recent Tweet read, “Happy fathers day!!! Goin to dinner with my family and the most amazing dad ever! I love you daddy!”)

Facebook and MySpace also figure into Warner’s new-media campaign, the latter particularly as an “important streaming partner,” Welt says. MySpace is streaming two tracks from “Guilty Pleasure,” and Grant expects the site to feature the entire album before release date.

In the realm of retail, Grant says Target and Wal-Mart will sell exclusive editions of the album with bonus material, while a direct-to-consumer version will feature six posters and two extra songs.

Once “Guilty Pleasure” is out, Tisdale says she hopes to tour the United States and Europe (where the set was released earlier this month). “This album is so important to me,” she says. “I really want to support it as much as I can. You put your heart and soul into something and it makes you a little bit vulnerable. It is who I am — hopefully people will like that.”