I enjoy singing, but I don't think I could do it a cappella style, without musical instrument accompaniment in the background.
Yeah, a cappella seems like since your voice is the only thing making sound, there is nothing to hide behind if you are off key!
Yes, and I need to hide the fact that I am a poor vocalist behind very loud music, especially when I'm in my car, lol.
Ha!  Very true for me as well.  When was a capella created and popular?
It's definitely got its origins in religion, with Chinese opera, Hindustani music, and other forms of gospels and hymns. Unsurprising, right?