Aly & AJ debuted back in early 2005, when their cover of The Lovin' Spoonful's "Do You Believe in Magic" was featured on Radio Disney and became a stunning #1-hit. The song first debuted in Now You See It..., the Disney Channel film Aly starred in. Under surveillance of Hollywood Records, Aly & AJ have released many more songs for different films as part of their contract with Disney. "No One" was used during the main titles of the Walt Disney film Ice Princess, just like their cover of Katrina and the Waves' "Walking on Sunshine" was used in the motion picture Herbie: Fully Loaded. Not long after, Aly & AJ Concert took place on July 24, 2005 at the Henry Fonda theater, located in Hollywood, California. Songs from their August-released debut album, 'Into the Rush', were performed for the first time, and later released on DVD. The album was heavily promoted due to the success of "Do You Believe in Magic" and went to #36 on the Billboard 200, the albums chart in the United States. Their mainstream first single "Rush" became their first hit on the Hot 100.

During the release of several Radio Disney singles, the girls opened for The Cheetah Girls in December 2005 for their Cheetah-licious Christmas Tour. In al that time, they kept recording, up to a point the record label decided to re-release the album. That became the 'Into the Rush: Deluxe Edition', which featured 3 new tracks and two remastered songs. The album was preceded by "Chemicals React", the first single from the deluxe edition, that got a release in August 2006. A month later, on September 19, 2006, the news came out that Aly & AJ were nominated for Contemporary Inspirational Artist of the Year (also known as Christian Artist of the Year) for the 2006 American Music Awards, which were held on November 21, 2006. They unfortunately did not take home the award, Gospel artist Kirk Franklin was presented with the award for his first time instead. Besides their nomination, they also introduced Nelly Furtado's performance of "Say It Right", along with 2006's Dancing With the Stars runner-up Mario Lopez.

On September 26, 2006, their holiday album, 'Acoustic Hearts of Winter' was released. On it, the Michalka sisters perform traditional Christmas songs including "Let It Snow" and "Silent Night" as well as original songs, "Greatest Time of Year" and "Not This Year". "Greatest Time of Year" was the first and only single from the album, which featured scenes from the Santa Clause 3 movie.

On May 8, 2007, a brief clip of their new single called "Potential Breakup Song" was leaked. Not long after the full Disney Radio version leaked. The girls performed the song at numerous TV shows, promoted the song heavily. Their new album, 'Insomniatic' was released on July 10, 2007, which also was the date their dual film Super Sweet 16: The Movie came out on DVD. They also co-hosted at TRL the week prior to the album release. "Potential Breakup Song" became their biggest hit to date, peaking at #17 in the U.S, #16 in Ireland, #18 in Norway and #22 in the UK. The song especially stood out because of its music video and lyrics.

In December '07, the news came out that "Like Whoa" would be the second single. At the end of the month, they performed a cover version of Katie Tunstall's "Black Horse and the Cherry Tree" for Pepsi Smash, viewable on Yahoo! Music. The song was also included on the re-release of 'Insomniatic' (March 2008), which is only available in Japan. In March also, Randy Jackson's 'Music Club, Vol. 1', a compilation with songs by many artists was released. One of the bonus tracks on the album is Aly & AJ's cover of "We're an American Band", a song originally sung by Grand Funk Railroad. A month later, in April, they announced in an interview with Radio Disney, that they were working on a new album, which was going to be more rock-influenced. An indication for the fans, no more singles from 'Insomniatic', much to their dismay.