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?”
“And why do I say,” says he, that in our case this is unprofitable, and that only useful which is clear and easy to be apprehended by the hearers? Since even in musical instruments without life one may see this: for whether it be pipe or harp, yet if it be struck or blown confusedly and unskilfully, without proper cadence or harmony, it will captivate none of the hearers. For even in these inarticulate sounds there is need of some distinctness: and if you strike not or breathe into the pipe according to art, you have done nothing. Now if from things without life we require so much distinctness, and harmony, and appropriateness, and into those inarticulate sounds we strive and contend to infuse so much meaning, much more in men indued with life and reason, and in spiritual gifts, ought one to make significancy an object.
Source: Homilies on First Corinthians (New Advent)