Freegal Music provides unlimited ad-free music streaming in conjunction with your local library. The catalogue is not as comprehensive as Spotify etc but there's a lot of popular artists, genres etc on there. 15 million tracks supposedly.
You can also download DRM-free MP3s but there's a limit of 5 per week.
You can stream in-browser using this link, or download iOS/Android apps.
Just to be clear, you'll need a valid Library card number to access the service. Dublin City Libraries is working for me, and many other Irish libraries are added.
Yes, you need a library card number. (During the pandemic you could get these without going to the library; i'm not sure if that is still the case)
If you click login and enter nothing apart from Ireland it shows a list of supported library systems - Cork City, Dublin City etc. Then just click one of them and enter your card # and PIN.
You can register online with Kildarecc for a library number, a temp one is given immediately so you never need to get the physical card. I used the temp one and it worked for Freegal