John Wesley provides some Instructions on Singing.
That this part of divine worship may be more acceptable to God, as well as more profitable to yourself and others, be careful to observe the following directions:
1. SING ALL
See that you join with the congregation as frequently as you can. Let not a slight degree of weakness or weariness hinder you. If it is a cross to you, take it up, and you will find a blessing.
2. SING LUSTILY AND WITH A GOOD COURAGE
Beware of singing as if you were half dead, or half asleep; but lift up your voice with strength. Be no more afraid of your voice now, nor more ashamed of its being, heard, than when you sung the songs of Satan.
3. SING MODESTLY
Do not bawl, so as to be heard above, or distinct from, the rest of the congregation, that you may not destroy the harmony; but strive to unite your voices together, so as to make one clear melodious sound.
4. SING IN TIME
Whatever time is sung, be sure to keep with it. Do not run before, nor stay behind it; but attend closely to the leading voices, and move therewith as exactly as you can. And take care you sing not too slow. This drawling way naturally steals on all who are lazy; and it is high time to drive it out from among us, and sing all our tunes just as quick as we did at first.
5. ABOVE ALL, SING SPIRITUALLY