Mechanicsburg has a rich marching band tradition going back to 1929. They began competing in the Tournament of Bands in 1989.

This was a successful year for the band which won every competition it entered up to the Tournament of Bands Atlantic Coast championship.

The 2005 show was entitled "A Suite For Winter". The band claimed 1st place prize on the night of November 12, 2005 at Lackawanna County Stadium in Moosic, PA. The band won first place in Group III with a score of 98.80, the highest score ever in TOB history (tying Mechanicsburg's 98.80 Group IV output in 1994). The show also earned the caption awards for high music, visual, and brass.

The band successfully defended its title on November 12, 2006 when they again won the TOB Group III Atlantic Coast Championships. Their show, entitled "Flight" earned a score of 98.05 despite being performed in the down-pouring rain at Lackawanna County Stadium. In addition to the first place finish, they were awarded the trophies for high music, visual, percussion, and auxiliary.

This performance would be one of the last ever put on at Lackawanna County Stadium, as the complex and baseball team, the Wilkes-Barre/Scranton Red Barons, would be bought out by the New York Yankees as a new affiliate. The artificial turf was removed the day after ACCs ended and replaced with a natural grass surface, ending Lackawanna County Stadium's (now PNC Field) long 23-year history hosting the Atlantic Coast Championships.

On November 10, 2007 the MASH band performed their 2007 show, "An Irish Heritage" and won their third title in a row at the TOB Group III Atlantic Coast Championships at the Delaware State University's Alumni Stadium in Dover, DE with a record-tying score of 98.80 (Set by themselves, twice). They were additionally awarded for high music, visual, auxiliary, and brass.

On November 16, 2008 at J. Birney Crum Stadium in Allentown, PA, the band performed their show "Above the Clouds" and won their fourth straight Group III TOB ACC title with a score of 97.35. The class of 2009 subsequently became the first Mechanicsburg graduates to ever win four straight championships. The band also took home awards for high music, visual, brass and percussion. This was the band's final year under director Dane Hildebrand. Hildebrand finished his 10th year as Mechanicsburg's director on high note, winning for the sixth time.

The band won its fifth consecutive Group III TOB Atlantic Coast Championship at Hersheypark Stadium in Hershey, PA on November 1, 2009. The Sunday night performance of their field show "Earth" earned them a score of 96.85 along with high music, visual, percussion, and auxiliary. It was their 11th ACC victory in school history, having already won Group IV in 1992, '94, '95, and '96, and Group III in '99, 2000, '05, '06, '07, and '08. They continue to hold the Group III high-score record (98.80 in 2005 and 2007) and the Group IV record (98.80 in 1994). These three 98.80s also stand as the overall highest scores received in the history of Tournament Of Bands. It was the first season with new band director Michael Drobish.

Their scores at the Atlantic Coast Championships are: