The reading is the kun'yomi reading, which you didn't learn. In order to learn it, think of this:
I almost always tune (つね) my violin, but today I didn't tune it. So, now I sound terrible. Imagine how terrible my untuned violin sounds, compared to how it always sounds.
My mom didn't always seem to be attracted to my dad.
Lately, I'm almost always asleep by ten.
It takes some kids a while to realize their parents aren’t always right.