what dose the popularity bar mean
The popularity bar is based on sales in the iTunes Store, and is relative to the other songs in the current display.
The most popular song in the list you are viewing has the full bar, and the other songs are relative to that.
In the iTunes store it's a measure of the 'popularity' of the items of what you are viewing e.g. if viewing an album then if all tracks have all bars filled then everyone (or such that it can't be distinguished) who has downloaded one track has also downloaded all other tracks ; if one track has twice as many bars as another track then that track has had twice as many downloads. It's potentially useful if looking at artists that you don't know about e.g. to see what other have been downloading for them
popularity bar
