It's not butter, it's Mendelssohn

Wilhelm Furtwangler and his German manager, a man named Mendelssohn,
are walking in downtown Berlin. Furtwangler sees a record shop and
decides to go in and see how sales of his records are doing. His manager
goes with him.

He goes up to the young clerk and says, "Do you have Beethoven's 5th Symphony conducted by Furtwangler?

The clerk checks and says, "No, we have recordings by Bruno Walter and Toscanini, but
no Furtwangler."

So Furtwangler asks, "Well, do you have Beethoven's 7th symphony conducted by Furtwangler?"

The clerk checks again and says, "No, we have recordings with Knappertsbusch, Muck and Krauss,but no Furtwangler." This goes on for a while, with the 3rd, 4th and 6th symphonies, the Missa Solemnis, and Fidelio.

No Furtwangler.

Finally,Furtwangler says in exasperation, "Don't you have ANY Beethoven conducted
by Furtwangler?"

And the clerk, equally annoyed, says, "Who the hell is this Furtwangler anyway?

Furtwangler says indignantly, "I am Furtwangler!"

The clerk points to the manager and says, sarcastically "Oh, right, and
I suppose this is Beethoven."

Furtwangler says, "No, that's Mendelssohn."