Crust on top is not the distinguishing feature between pies and tarts. Tarts often have top crusts. The only consistent difference is the angle and sturdiness of the sides - tarts have vertical (or nearly), sturdy sides, pies have angled sides that are less sturdy.

A song about it

This is half-true. Both versions are acceptable for most, possibly all emotions.

Eg ‘fearg’ is anger, which would be on you. “tá fearg orm” ~ Anger is on me

‘feargach’ is angry, which you can be. “táim feargach” ~ i am angry