2 Chronicles 5:13

The trumpeters and singers joined in unison, as with one voice, to give praise and thanks to the LORD. Accompanied by trumpets, cymbals and other instruments, they raised their voices in praise to the LORD and sang:
"He is good;
his love endures forever."
Then the temple of the LORD was filled with a cloud,

Whoa! A new instrument! Up until this point, singing in the temple has been accompanied by harps, lyres, and cymbals. Now, the trumpet is introduced into worship, and not just as an accompaniment instrument, but in unison with the singers, as with one voice (hmm…the title of Augsburg Fortress's hymnal supplement, With One Voice).

Don’t picture a modern orchestral trumpet. Picture a shofar, a ram’s horn. No valves, no yards of tubing, just a hollowed out ram’s horn. If you have ever tried to play a modern trumpet (or any brass instrument for that matter) without using any valves, just using the buzzing of your lips and the tightening of your embouchure to play the scale, then you know that either you have to be a really good trumpeter to play a scale without valves, or you won’t be playing many notes—you’ll just sound like a person at a parade or ball game with a plastic trumpet just making a lot of noise.

It really makes you wonder what the melody of the singing was like if it was accompanied by a ram’s horn that had no valves and couldn’t play many notes of the harmonic overtone series.

But getting past the physics of the instrument and the shape of the melody, what is going on in this passage? All the musicians of the temple are joining together to give praise and thanks to YHWH, the God of the Promise, for allowing the the Ark of the Covenant to return to Jerusalem. And do the words of the song sound familiar? Many Christians say these words as part of their after meal prayers (“Oh, give thanks to the LORD, for he is good, for his mercy endures forever. Amen.”)

And was God pleased or what!?! His glory filled the temple, just like He led the Children of Israel with the pillar of cloud through the exodus and wandering in the wilderness. Isaiah talks about the same cloud filling the temple and Martin Luther penned this picture into his hymn Isaiah, Mighty Seer, in Days of Old.

So what is the singing application for us?

1. Praise God with instruments and singing together (believe it or not, in the desk of my first teacher’s desk, was a pamphlet explaining why instruments should NOT be used in worship!).
2. Raise your voice to the LORD (to me, that implies volume, more than normal)
3. Sing of God’s goodness and love (i.e. tell why you are praising him—what has he done for you?)

Shofar Sounders Webpage
Strong's H7782 "trumpet" vs. H2689 "trumpets"