I have Sirius (actually XM) radios in both cars AND a unit in my home. I have not listened to "mainstream" radio in nearly 3 years.
Not a one of them now plays anything older than the mid 70's--all the old 50's and 60's stations are long gone.
I will admit that their customer services needs a little work. When I was trying to "transfer" the one radio to a new car I just bought, customer service hung up on me 3 different times!! When I decided to try their website customer service, I explained what I wanted to do. The rep on the other end told me he couldn't actually help me, but would recommend the # to call!!!!
Anyway, I FINALLY got an English speaking rep who understood the simple thing I wanted to do, and she did it for me..as the others should have done the 3 previous times I called.