Mantra is the language of the Heart, no doubt, but you can still talk to yourself a certain way, particularly in song, that touches the same spot - Self to Self as it were - meaning that it's like speaking to the higher self within... sometimes invoking, sometimes requesting, sometimes reasoning, sometimes arguing, sometimes demanding, always reminding. If it's real you can use any kind of language. At least in any of those moments when you talk that way, and your heart is in it, you are sincere, and the Divine knows that and may give an indication of having heard - in solace, in comfort, in harmony.
This is from a collection of songs. They weren't written with an aim to say anything to anyone in particular. They are expression of an aspiration, a way of talking to yourself trying to find a way to touch that spot - Self to Self.