In German, there is an idiom "Hier spielt die Musik!" (with intonationally emphasized "hier"). Translated literally: "Here is the music playing!" It is used with an accompanying pointing gesture to direct/point someone's attention to oneself or to a specific point in space/location. It is mainly used to grab someone's attention, or to regrab her attention because the person had become distracted by something else.
In plain words, you could say: "Look here/at me (again)!", "Listen to me (again)!", or more generally (but less correct): "Pay attention to here/me (again)!"
Does an idiom with the same function exist in English?
If you are a native speaker and not aware of such an idiom then an answer like "I am a native speaker and not aware of such an idiom" is absolutely fine and will be highly appreciated.