Since hearing "good music" is a good thing -- saying "That's music to my ears" means "That sounds good to me.". That phrase is an idiom. "Music to my ears" means that there is something that I have wanted and now it is here. For example: The online store that I ordered a book from has not got it.What does the idiom all ears mean?
Meaning of Idiom ‘All Ears’. To be all ears means to be listening closely; to be eager to hear something; to play close attention when being told something or to be willing to pay close attention. The most common use of the idiom is in the phrase “I’m all ears.”. Examples: “I heard you had an idea for the project. I’m all ears.”.