I like this one better.
There's 5 different performances up on youtube from the same event, old lady has got some pipes (too bad this is shit).
My art history prof from undergrad has done a lot of major writing on Yoko. During her 70th birthday celebration he participated in a performance piece consisting of the both of them, Yoko and my teacher, entering a large bag and then getting naked. He's committed to her artistic practice, to put it lightly.