Beca, an introverted and musically gifted freshman at Barden University, dreams of becoming a producer and DJ. Reluctantly arriving at college under her father's insistence, she finds herself out of tune with the traditional college experience. Her passion for music quickly captures the attention of the a cappella scene when she is overheard singing in the shower by Chloe, a member of the Bellas, an all-female a cappella group struggling to regain their status after a humiliating loss at the previous year's national competition. Pressured by Chloe and seeking an extracurricular requirement, Beca reluctantly auditions for and ultimately joins the talismanic ensemble.

The Bellas, stereotyped for their stiff performances and rigid repertoire, are led by the controlling and image-obsessed Aubrey, who clashes with Beca's innovative ideas and desire to refresh the group's music and image. As the Bellas work toward reinventing themselves, the group's dynamics begin to shift, with Beca's modern influences challenging Aubrey's traditionalist views. The team must navigate their differences and personal struggles as they prepare to compete in the cutthroat college a cappella circuit against their all-male rivals, the Treblemakers, who are not only current champions but also embody the charismatic and contemporary edge that Beca believes the Bellas need to adopt to survive and thrive on the stage.