Singing

"Come, let us sing for joy to the Lord; let us shout aloud to the Rock of our salvation. Let us come before him with thanksgiving and extol him with music and song." 

Psalm 95:1-2

Singing is an important part of church services, it's a form of worship. King David wrote the Psalms to be songs for worship, so singing has been part of worship for a long time. I didn't like singing in church when I was younger, but I finally wised up and started singing in church; I'll just say God was working on me and succeeded, thankfully. The quote below is from John Wesley (he contributed to the formation of Methodism) in Select Hymns with Tunes Annext. I think Wesley sets a good example for how we should sing for the Lord. These are Wesley's "Directions for Congregational Singing":

“That this part of Divine Worship may be more acceptable to God, as well as the more profitable to yourself and others, be careful to observe the following directions:

• Learn these tunes before you learn any others, afterwards learn as many as you please.
• Sing them exactly as they are printed here, without altering or mending them at all; and if you have learned to sing them otherwise, unlearn it as soon as you can.
• Sing All – see that you join 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.
• Sing Lustily – and with 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 sang the songs of Satan.
• 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 melodious sound.
• Sing in time – whatever time is sung, be sure to keep with it. Do not run before and do not stay behind it; but attend closely to the leading voices and move therewith as exactly as you can and take care not to sing 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.
• Sing spiritually – have an eye to God in every word you sing. Aim at pleasing Him more than yourself, or any other creature. In order to attend strictly to the sense of what you sing, and see that your heart is not carried away with the sound, but offered to God continually; so shall your singing be such as the Lord will approve here, and reward when he cometh in the clouds of heaven.”

I found the text here: 

http://www.biblicalworship.com/john-wesleys-directions-for-congregational-singing-1761/