The 65-year-old made the revelation to sometime QOTSA drummer Dave Grohl, who was guest presenting the US TV show Chelsea Lately.
But the singer/songwriter/pianist/diva admitted the experience was a little unusual, having joined Josh Homme and the boys after recording with Engelbert Humperdinck.
He told Grohl: "I went down and sang with him and then drove three blocks, in the Valley, I went from Engelbert to Queens of the Stone Age, which was, you know, a bit of a mind-fuck."
Grohl told of how the dry-witted Elton asked the QOTSA guys whether he would be playing a ballad and also said he is not often asked to contribute to other artists' albums because they assume he will turn them down.
But he pointed out that he played on Alice In Chains' Black Gives Way To Blue in 2009.
The new QOTSA album is due out this year.