In the book of Chronicles (chapter 5, verses 13 and 14) we see the following:

The trumpeters and musicians joined in unison to give praise and thanks to the Lord. Accompanied by trumpets, cymbals and other instruments, the singers raised their voices in praise to the Lord and sang:
    ‘He is good;
    his love endures for ever.’
Then the temple of the Lord was filled with the cloud, and the priests could not perform their service because of the cloud, for the glory of the Lord filled the temple of God.

When we sing and worship we are not just singing songs.  We are coming before God.  We want Him to meet with us as He did with the Israelites.