People really do say this to singers. It's SO ODD! It's like saying "You're an accountant? Do my taxes. NOW!" Or saying to a landscape architect, "Landscape my property. NOW!" Who likes to be put on the spot like that?
Who puts people on the spot like that, anyway?
Here are a few answers I've heard, ranging from downright sassy to politely diplomatic. Because I honestly don't know what the most appropriate response is, but maybe different demands can be answered with different responses.
The Sassy Response
One of the best responses to this was from my friend Susannah in Grad school at the Manhattan School of Music. She was working in an office and many people demanded she sings something right there--on the spot. She responded smiling with, "I charge by the note." They stopped demanding.
Another friend from college, Joe, responds with some variation of "I'm sorry, the monkey only dances if you put money in the cup." (Ouch!)
The Commercial Response
"If you would like to hear me sing, just put my name in at iTunes and you can download any of 3 songs I have there." Unfortunately, that didn't stop the pushy people from pleading, so I gave them a free download card. (What happened next is a WHOLE other blog article...) They finally left me alone because someone else distracted them. By playing the song previews on iTunes. Go figure.
Give 'em What They Want
Amazingly, a couple of my friends actually break into song, like "O sole mio" or whatever they have in their head at that moment. Amazing.
The Diplomatic Response
David, a friend of mine whose skill ranges from enchanting 60s folk medley to lovely early English song, will frequently respond with "I'm not warmed up and I don't want to damage my voice." Very fact-based, very diplomatic. Like Marta, who simply says, "Sorry, I'm off-duty." (That's my favorite so far.)
The Audience-Building Response
From fellow mezzo MajaLisa: "I can't sing for you now, but you are welcome to come hear me at my upcoming performance of ________. If you want to give me your email address, I can add you to my newsletter." NICE, MajaLisa, very nice! We can learn from this woman!
A Parent's Response
Leave it to a parent-singer-conductor to give the most entertaing response: "When people demand that I sing for them, I break into a lively rendition of "The Wheels on the Bus (Go 'Round and 'Round)" and insist they do the actions with me."