by using yahoo radio music, does it cost anything or is it free?

Answer 1

Regular Launchcast is free, although you do pay for it in a sense because they sprinkle advertisements in between the songs sometimes. There is a paid (Plus) version which eliminates the ads and gives other benefits, but you are not obligated to buy the paid version (although, imho, the paid version is well worth it IF you listen regularly). You can just listen to the free version "forever".

Answer 2

AIN"T NOTHING FREE