Select the funnel from the visualizations (1), select track in the field list (2) and drag track to the values box (3). (Image 5 below) Now we need to customize this visualization. Select the paint brush to edit. (Image 6 below) I recommend giving each of the tracks a different color. Since Tracks are determined by the organizer the data maybe similar so you might want to use the same colors for more than one data point. You should also update the title Count of Tracks by Track sounds silly. Now we have a lovely display of session distribution by track.
She came up with a nice-looking set of information describing sessions and presenters for SQL Saturday Nashville 2016. I love seeing this kind of thing and hope it becomes mainstream among SQL Saturday organizers (maybe to the point where some of this is built into the SQL Saturday website).