Translation
Even the lifeless things giving a sound, whether a flute or a harp, if a distinction to the sounds is not given, how will what is being piped or being harped be known?
Paraphrase
Allow me to give an example that is connected to the way you speak in tongues. Musical instruments create beautiful music by playing a variety of notes with different timing. But if you play the same note over and over again, how can any beauty be found in that? Since your speaking in tongues is just as monotonous and repetitive as that would be, it should be obvious that what you are doing has no meaning.