Josh: I know it’s late, but would you like to stay for dinner?
Betty: That’s music to my ears. I’m starving.

When we hear something that makes us happy, we can describe it as “music to our ears”. In this example, Betty liked what Josh said, but it can refer to sounds other than speech as well. For example, the sound of construction is loud and irritating, but if you own the building being made, it could be music to your ears.