Doron, each star is a single note or a cluster of notes that make up the sound, usually a chord. Each row represents each measure; row one, measure one, etc.,and there will be as many rows as there are measures in the rhythm. (This works a little differently in the sequencer, where the measure increases for the duration of the sequenced song.) Even though there may be only one star on the line, there may be six different notes included in that particular cluster. Check it out - it's a learn as you go sort of thing.