Near the end of Robert Priest’s show, I get waved onstage to sit in. Bob Cohen starts flashing chord shapes at me helpful like hand puppetry. I say, “No thanks, it’s fine, I’ll improvise.” This is code for I am listening instead of counting. His concern stems probably from the song being transposed, which is musician-speak for everything you knew is repositioned. But that concerns him differently than me because I never knew the original sequence anyway. Bob, however, continues calling out chord changes, like kind guy that he is ensuring no errors and sensitive to the stranger. An air-traffic controller that doesn’t trust radar. Unfortunately, it makes playing by ear harder, because he keeps solving the problems I wish to calculate on my own. But okay. I comply. It’s simpler and quicker. It’s also a guarantee I won’t play incorrectly.

Then he says, “F.”

So I give him F. Not a shy F. A full-blown, eight-finger, federal-grade F major, loud enough to obtain a hunting license. The room reacts the way rooms do when something has gone medically wrong. Because the song is in B minor, there is no F. There has never been an F. F is not even emotionally adjacent to this song. We carry on and I assume the mistake stems from him transposing internally. Humans are complicated machines with poor firmware updates.

After the song ends, I ask purely for science “Why did you tell me to go to F?” Bob says, perfectly calm: I wanted to hear you make a mistake. There we go. Experimental music.