Here's an interesting twist...hopefully I won't stray into forbidden topic territory.

We usually rehearse on Wednesday nights for the upcoming Sunday AM service.  Now some rehearsals are about what you'd expect...boring and routine.  Other rehearsals cross that line of just rehearsing music and become a worship experience.  I would tend to call the later worship songs and the former not...even if it was the same song on different Wednesday nights.  

In a similar vein, when I was recovering from chemo/radiation, Wednesday rehearsals were approached with a significant amount of dread and apprehension as they were pretty painful experiences, mostly emotionally as I knew I was playing extremely poorly, but sometimes physically.  Worship content could be zero or even negative.  The same songs being played Sunday AM took on a new character and I rarely had a really bad time playing then...usually positive worship content.

To make it even more interesting... I know that every person is reacting in a different way during Wednesday and Sunday.  Some Sunday mornings are a total train wreck musically or technically, but that generally seems to be when there's significant feedback about how meaningful a worship service it was for many in the congregation.

Perhaps I'm splitting hairs semantically, but its seems like calling a song a worship song is a bit of a mischaracterization...kind of like saying a particular kind of architecture is worship architecture or a particular kind of food is worship food (would probably be Tex-Mex though.) Sure, some styles/details of architecture in various cultures/eras have become associated with worship, like a steeple or mineret, but they doesn't really mean that in and of themselves.

--David