Do you have a music service with a subscription linked with your Google Nest speaker?
The music that is played can depend on if you have a subscription or not? Please have a look at the Google Nest help center link below for more information.
I just wanted to jump in real fast to see if you saw Cathal_S and RachelGomez123 reply and to see if you still needed some help on this or if you were able to get it sorted out. They are correct, a premium subscription is needed for you to be able to ask for a specific song, artist or playlist. Please, double-check your subscription if it has a premium subs and also, kindly check the link provided above for more info. If you are still needing some help, just let us know and we'll be happy to continue helping.