This can only happen when you are on a full multiplex system. Those KJs who use multiplex disc will know that you need to go to 'L' for most songs and in some discs it is the R channel that have no vocal. Most of our discs have the original singer/artist on the the vocal guild channel.
On many occasion when I was still active hosting at the bar, I came across some very good singers. They can be so good that I thought I was on the wrong channel and hearing the original artist, which made me press the channel button to get rid of the original. Of course I will now have two voices singing. Then I had to quickly revert back to the correct channel. After the song finish I normally come around that table and compliment the singer personally while explaining the mistake.
Saturday night I was at this bar. The host did the above to me. That was the biggest complement. Some night I can just get it right.
Mean a lot for an ex- Badsinger.
Anyone have similar experience to share.