I'm so glad that I signed up for the Google Play Music All Access subscription way back when they first offered it as a promo. Because of it, despite them having killed off of Play Music, I still have a $7.99 subscription that will never change in price, and it comes with free music on YT Music, and ZERO ads on YT music or YouTube itself, and more that I can't remember off the top of my head.
Meanwhile, if someone new wanted to get the same, the entry price is now, what, *quick checks* $13.99/mo for a single person (or $139.99/yr), or $22.99/mo for a family, and $10.99 for just YT Music premium.
The only way to get the $7.99/mo now is to be a student (and they have to verify you are one).
en.wikipedia.org