Albert Barnes Commentary 1 Corinthians 14:7

"Even things without life, giving a voice, whether pipe or harp, if they give not a distinction in the sounds, how shall it be known what is piped or harped?" — 1 Corinthians 14:7 (ASV)

Things without life. Instruments of music.

Whether pipe. This instrument (aulov) was usually made of reeds and probably resembled a flageolet.

Or harp. This instrument (kiyara) was a stringed instrument, made in the same way as a modern harp. It usually had ten strings and was struck with the plectrum or with a key. It was commonly employed in praise.

Except they give a distinction in the sounds. Unless they give a difference in the tones, such as are indicated on the musical scale.

How shall it be known, etc. That is, there would be no rhythm, no music. Nothing would be indicated by it. It would not be fitted to excite the emotions of sorrow or joy. All music is designed to excite emotions; but if there is no difference in the tones, no emotion would be produced.

So it would be in words uttered. Unless there was something fitted to excite thought or emotion; unless what was spoken was made intelligible—no matter how important in itself it might be—it would still be useless.