Spotify or Pandora


A relative pointed out two music download websites: Spotify and Pandora. I don't know anything about music downloads. But I was hoping to stream hi-rez original artist oldies. I tried one selection on Spotify and it sounded like MP3 quality and didn't seem like original artists were singing.

Please advise. I would love to stream in hi-rez oldies from the 50s and 60s, but don't know if Spotify or Pandora are good sources.

Thanks
bifwynne
I prefer Spotify because it is totally free and I can also use a great Spotify album downloader for Mac to help me extract all the songs for free listening offline.  https://www.drmare.com/spotify-music-converter-for-mac/
Just went on Tidal web site.  OK, ... so walk me through how I get the Tidal music into my linestage.  I do not have a DAC, other than what is in my PC.  So the music signal from the PC to the linestage has to be in analogue format.

So, how do I connect my PC to my linestage in analogue mode.  Is there a UBC jack to SE or XLR/BAL type connector cord to make the connection?  Is the UBC jack a digital output? If so, would I have to use the headphone output jack of my PC??  But how do I connect that to the input jacks of my linestage (SE or XLR/BAL)??

Also, is the DAC in my PC inferior to a separate stand-alone DAC unit? If so, how much SQ  would I lose by not having a dedicated DAC?

I am a older member of the baby boomer generation.  So this is all new to me.

Thanks.    
@bifwynne 
Yes, you should get a separate DAC. 
If you want something inexpensive, get a Bluesound Node. It has great connectivity with other apps and you can buy a better DAC, should you want to.
I use the Bluesound with an Ayre Codex, and I think it a very good path to streaming music.