Does it matter if your playing at home vs stage?
Wherever - if it works, it works ...
That's all fine Randy until the requests start coming.. Lol
When a request comes in, if the song is not set up in the 'songbook' or whatever, a "Performing Pro" knows enough about his/her KB to pick the right style for the song - or D/L an MP3 on a tablet, iPad, smart phone whatever ...
OR, simply say "I'm sorry, I don't know that one, is there something else you would like to hear?" ...