Original sentence: Hot Mainstream Rock Tracks is a ranking in Billboard magazine of the most-played songs on mainstream rock radio stations, a category that includes stations that play primarily rock music but are not modern rock (that is, "alternative") stations, which are counted in the Hot Alternative Tracks chart
Edited sentence: Hot Mainstream Rock Tracks is a ranking in Billboard magazine of the most-played songs on mainstream rock radio stations, a category that includes stations that play primarily rock music but are not modern rock (that is, "alternative") stations, which are counted in the Alternative Songs chart