The dash - number is the current position in the playlist. Go to menu item External Devices - as I recall - so that one sees the current selection playing and the >| and |< symbols, select one to increment or decrement that position number.
Scepticism and Animal Faith (1923)
Scepticism is the chastity of the intellect, and it is shameful to surrender it too soon or to the first comer: there is nobility in preserving it coolly and proudly through long youth, until at last, in the ripeness of instinct and discretion, it can be safely exchanged for fidelity and happiness. (The Works of George Santayana p. 65)
Eschew eristical argumentation. I am responsible for what I write, not for your understanding of it.