When a MIDI file has been imported or dragged into the Groove Lock field, a series of small blue dots will appear directly below the Arpeggiator steps. These dots serve a dual purpose. They confirm that Groove Lock has received MIDI data and provide a visual reference for the feel of the MIDI content. Changing the Arpeggiator’s Clock value will change the resolution of the blue dots.

Arpeggiator Clock set to 1/8

Arpeggiator Clock set to 1/16

The Groove Lock feature uses the timing and note values of the MIDI content, not the melodic value. This means that Omnisphere locks to the feel or groove of the clip, not to the musical pattern itself. This applies to polyphonic MIDI files as well.