This may be my best example of contrast. Kraftwerk at Kuntsammlung Nordheim-Wastfallen, Dusseldorf, January 2013. They are performing Electrokardiogram from the backing visuals. Signed quite boldy in silver paint pen by the existing members in 2013/2014. I am so torn though - this is a just a photograph printed on something like Fuji-paper or the like. Even Kodak - it is not an Official product. But the signatures they give in the last years are awful - these are near miraculous. Or, you only get a few, not all 4. And Falk does't sign his full name anymore - just initials. That also pins the date. The angles they chose to sign at show some intent I think. I assume you know them - they influenced Hip-Hop in an astounding way back in 1981 (Numeren/Numbers) and they were well known for the 1975 Autobahn which I saw live 40 years later. Also Radioactivity on the Hiroshima anniversary. "Turn the dials with your hand, till you find the short wave band...".

Below is a Dutch poster, the 8x10 and a set of glasses from when I saw them at the Wang Theater in 2015.