A user interface implemented on a touch-sensitive display for a virtual musical instrument comprising a plurality of chord touch regions configured in a predetermined sequence, each chord touch region corresponding to a chord in a musical key and being divided into a plurality of separate touch zones, the plurality of chord touch regions defining a predetermined set of chords, where each of the plurality of separate touch zones in each region is associated with one or more preselected MIDI files stored in a computer-readable medium. Each of the plurality of touch zones is configured to detect one or more of a plurality of touch gesture articulations including at least one of a legato articulation, a pizzicato articulation, or a staccato articulation. The one or more of the plurality of touch gesture articulations determines the preselected MIDI file associated with each of the plurality of separate touch zones.