Here’s a website that Hal told me about.
It allows you to set up one or more "radio stations" based on your own musical criteria. It seems oriented to popular and jazz music (it doesn’t know from classical).
You define your criteria (I now have 2 stations – Ella Fitzgerald, Benny Goodman) and it selects music from those artists and other similar artists and plays them non-stop without commercials or any other interruption. With each new piece of music you can grade it according to your taste and somehow the system remembers and adjusts its future selections based upon those fine tunings.
I love it – I open it all the time when I’m working on the computer and it’s terrific.
Give it a shot.