IIRC Play Music was a paid service, it probably had a free tier with ads/commercials, but I definitely paid for it. That’s how I got grandfathered into YouTube Premium (when they launched YouTube Red as it was called it came “free” with the subscription to Play Music) and can’t go back to the free tier or deal with the various hacked clients and ad blockers. It’s been over a decade of ad-free YouTube (except for the sponsor segments everyone does now, I do use SmartTube on my Nvidia Shield to skip those).