Abstract: A tape cartridge for use in the reproduction of sound recordings on a tape is characterized by a brake mechanism which moves in a linear direction toward and away from the rotating reel and hub which carry the tape. The brake mechanism consists of a unitary structure which is guided between two upstanding walls within the cartridge and a spring which is operatively connected to the unitary structure and urges it toward the reel. A pawl like projecting member is positioned on the outer periphery of the unitary structure and is designed to engage any one of the plurality of openings in the reel thereby preventing rotation of the reel. Disengagement of the pawl member from the reel enables rotation of the reel. The linear motion of the unitary brake structure enables the cartridge to be properly aligned when positioned within the tape recorder machine resulting in an even pressure pad contact and tape tracking.