LOS ANGELES — Demi Lovato didn’t have her own TV show, “Sonny With a Chance,” when she starred in the 2008 cable film “Camp Rock.” Her co-stars, the Jonas Brothers, were established musicians but had little acting experience.

That changed with “Camp Rock,” a summer-and-sun answer to “High School Musical.” The Disney Channel movie was the top-rated cable program in 2008 with more than 10 million total viewers. It was an even bigger hit with teens, tweens and kids.

Lovato and the Jonas Brothers, along with a better script and musical numbers, are headed back to the great outdoors for “Camp Rock 2: The Final Jam.” In the sequel, their beloved camp could close because of a flashy music camp across the lake.

How did the second time around compare to the first?

“The first movie was all of our first movies,” Lovato said. “This time around, I knew what to expect and was a little more seasoned as an actress. The first movie was really great, but I think we all stepped up our game for the second movie.”

Between films, Lovato and Joe Jonas recorded the duet “Make a Wave” to raise eco-awareness. In the film sequel they perform another duet, the romantic “I Wouldn’t Change a Thing.”

Lovato said she really connected with the “Camp Rock 2” tune because she and Joe Jonas have been friends for so many years.

“If I had just met him, it would have been more difficult to play those emotions,” Lovato said. “We have gone through a lot — not just me and him, but all three of the brothers. We’ve been through so much since the first ‘Camp Rock.’

“Joe and I have had our ups and downs, so it wasn’t difficult to relate to the song.”

Joe Jonas adds that any good relationship has its ups and downs. (That happens to be one of the many themes of “Camp Rock 2.”)

Joe Jonas isn’t the only one who gets a big musical number. Nick Jonas reveals a bit about himself in the tune he wrote, “Introducing Me.” But don’t believe everything you hear.

“Some of what’s in the song is true,” Nick Jonas said. “There’s a line that says I’m not into cars. That’s not really true. I love cars. Singing that line was a challenge.”

Kevin Jonas, who says he’s a klutz in real life, gets some of the bigger physical comedy moments.

Matthew “Mdot” Finley is the new face this time. He hopes to launch his acting and singing career with this film, and to release a rap album that doesn’t need a parental advisory.

In the movie, Mdot plays the competing camp’s brightest — and most egotistical — musical star. He says he enjoyed the Jonas Brothers’ down-to-earth style.

“This is my first major film so I was willing to lean on the other actors and the director to help get my acting chops. When I was done, I was ready to go do another film,” Mdot says.

An extended edition of “Camp Rock 2: The Final Jam” that features two exclusive new music numbers, is available on Blu-ray and DVD.

‘Camp Rock 2: The Final Jam’

When: 8 tonight

Where: Disney Channel