Abstract: A tape cassette includes an internal drive system which is engageable by a drive capstan of a tape cassette machine and which drives a recording tape of the cassette at a speed which is higher or lower than the speed at which the tape would be driven by the capstan alone. Where the tape speed is reduced, the playing time of the cassette is increased and the cassette is therefore less wasteful for speech recordings where a high tape speed is not necessary. The drive system can comprise a drive belt which is driven by the capstan and which passes around a pair of rollers, the tape being driven by means of one of the rollers. Alternatively, a rotatable member (such as a roller, a tubular sleeve or a gear) can be engaged by the capstan, and the tape is then driven by means of the rotatable member.