Long tail keywords - keyword density

So I know you have to optimize your article to increase the keyword density. But when it’s a long tail one, wouldn’t it be spammy?

Example: kw - “best music studio equipment for the beginners”

I can’t just stuff it in every paragraph, maybe 2-3 times AT MOST! and I get a red light from yoast.

So do I keep doing it this way or do I just use a short one like “music studio” just to increase the density?

You dont need to stuff it, 2-3 times is more than sufficient, it would be good if you can include it in h2, h3 or h4

Write for the reader, write for the reader, write for the reader.
If it sounds spammy? Don't do it.
You're better off mentioning it once in an H2, putting it in the URL, and once somewhere in the middle of the content.
Use synonyms and similar phrases throughout the content, too.
You could link to this long tail article from another supporting article.

I have great success doing it this way, and I ensure that the content is easy and fun to read.
Yoast can be helpful to remind you to do certain things, but you shouldn't follow its exact formula.
Plus, it just looks tacky when you write content in that way.
I no longer use it at all, haven't in a long time; my content is far better without it.
As a visitor, I quickly exit pages that are stuffed and don't read naturally; therefore, I don't post it.
If it's written for the search engine, it's definitely not doing your visitors any favors.

As a side note, I build completely white hat websites, I write all of my own content, and I do minimal link building by hand.
over 90% of my traffic is organic search, the other 10% is organic social traffic/direct.
I don't even send social signals- those are my visitors!
So, my method would be largely unpopular, but I've got solid sites with strong backbones!