At Murchison Middle School, almost a third of the students take band classes.
"The band program has expanded to nearly 500 students," said Director of Bands Whitney Crowley.
Those students are crammed into a space built for much fewer students, which has made practicing a challenge.
At close to 1,500 students, Murchison is the largest middle school in the district and teachers say the school is busting at the seams. Hundreds of kids spend their classes in portable buildings.
"They run on a different bell schedule and they transition differently because it you have 1,500 kids transition at the same time, it's a lot of kids," said assistant principal Rob Musfeldt.
As more families move into the district, portables are being used from elementary level to high school. The superintendent has estimated that roughly 20,000 kids spend at least part of their day in portables. Akins High School in South Austin has 20 portable buildings, the most within AISD. At some schools, like Zilker Elementary, portables could be considered permanent fixtures.
"The school was built in 1950 and we've had portables since 1953 so portables are a long standing issue here," said parent Jacquie Benestante.
She believes kids just can't get the same classroom experience in portables and wishes the district would do more to address the issue.
"I think we just want the district to have a plan in place now for allocating funds for a systematic replacement of portables."
AISD Executive Director of Facilities, Paul Turner, says the district is making an effort to ease overcrowding and cut down on the use of portables.
"What we try to focus on is the areas that are overcrowded to the point that we just absolutely in that area don't have enough capacity," he said.
But, getting rid of the AISD's 650 portables would cost far more than the district could ever afford.
"We're continuing to always look through those opportunities and try to work through them where we can," said Turner.
According to AISD, a proposed 2013 bond package would eliminate 16% of the district's portables by building on and opening new schools. Teachers and administrators at Murchison are hoping the bond package will go to a vote in May and be passed by voters in order for the school to get new fine arts and science wings.