Abstract: A system for playing media content items operates to provide smooth transitions between the media content items to continuously support a user's repetitive motion activity. The system can generate crossfade data containing information for transitions between media content items. The mix-in and mix-out points for the transitions are calculated to eliminate one or more portions of media content items that have lower musical energy than a majority portion of the items, and to maintain substantially consistent and/or stable musical energy (e.g., audio power or sound power) throughout the media content items including transitions therebetween.

Abstract: An electronic device may comprise audio processing circuitry and a universal serial bus (USB) connector having a first contact and a second contact. In a first mode of operation, the audio processing circuitry is configured to output one or more audio signals carrying music and/or voice via the first contact and the second contact. In a second mode of operation, the audio processing circuitry is configured to output a signal for delivering supply current via the first contact and the second contact. While the electronic device is in the first mode of operation, a gain and/or volume limit of the audio processing circuitry may be set to a first level, and while the electronic device is in the second mode of operation, the gain and/or volume limit of the audio processing circuitry may be set to a second level that is higher than the first level.

Abstract: Example techniques relate to playback queue subscriptions. An example implementation involves a computing system receiving, from a first computing device associated with a first user account, an instruction to enable subscription to a first playback queue associated with a first media playback system. In response to the instruction, the computing system enables second user accounts to subscribe to the first playback queue. The second user accounts are registered with respective second media playback systems in respective second household. The computing system receives, from a particular second media playback system, a request to subscribe to the first playback queue; and in response, sends one or more messages that update a control interface of the first control device to display a subscriber indication and (ii) sends one or more messages that populate a second playback queue of the particular second media playback system with audio tracks of the first playback queue.