Abstract: A tape-cassette of the now popularly standardized dual transfer-spool type, having identical top and bottom mating halves, including a slightly raised mesial anterior portion, having a pair of anterior aperatures for entry of a capstan-drive roller apposed to a central anterior aperture for entry of an electromagnetic-head. Wherein is provided a special "anti-jam" perimeter-declivity formation serving to ameliorate occasional jamming tendancy known to the standard squared perimeter cross-section manner of construction. The notably smooth-running characteristics of this otherwise successful cassette configuration are not in any way compromised, while now rendered virtually care-free as to loading procedure, even in a darkened room.