1 Corinthians 14:6-8

6But now, brethren, if I come to you speaking in tongues, what will I profit you unless I speak to you either by way of 1revelation or of 2knowledge or of 3prophecy or of 4teaching?

7Yet even lifeless things, either flute or harp, in producing a sound, if they do not produce a distinction in the tones, how will it be known what is played on the flute or on the harp?

8For if 5the 6bugle produces an indistinct sound, who will prepare himself for battle?