Just as another data point, I think the word 'deliberate' is entirely appropriate as it differentiates between 'casual' practice (e.g. just playing through a bunch of songs and hoping you get better) vs deliberate practice where you are working on a specific exercise with a specific goal. I can't really relate to what the parent post is saying.

I think it’s good to differentiate between ‘practice that makes a difference’ and ‘noodling about,’ in the words of my old teacher, which is practice that doesn’t concentrate on improving anything specific.

Is there a different word you’d choose? ‘Intentional’ is equally misused.

I hear what you're saying. On the other hand, "deliberate practice" is a term of art.

Deliberate practice is a jargon term in the world of learning a musical instrument.

I mean “deliberate” to be the adjective for “practice” and not “app”.

Thanks for the suggestion though. Definitely something to think about. I personally hate “opinionated” too.