1. A method comprising: presenting a user of a portable computing device with visual cues on a multi-touch sensitive display of the portable computing device, the presented visual cues indicative of temporally sequenced note selections in accord with a musical score, wherein the presentation of visual cues is in correspondence with a target tempo; capturing a sequence of note soundings expressed by the user using the portable computing device; and repeatedly recalculating a current value for the target tempo throughout a performance by the user and thereby varying, at least partially in correspondence with an actual performance tempo indicated by the captured note soundings, a pace at which visual cues for successive ones of the note selections arrive at a visual cue presentation zone of the multi-touch sensitive display.