"This Hohner harmonica ad appeared in The New York Times Sunday Magazine sometime during 1966".
When I searched the 'net for information I found this in a description of it on Evilbay:
"Isn't that what's-his-name playing a Hohner whatchamacallit?
What a hoot! If you are a Batman fan this you've gotta have!
EXTREMELY RARE, IMPOSSIBLE TO FIND Fifty year old ROBIN advertisement.
READY TO FRAME. Dimensions are 13 9/16 inches by 10 7/16 inches".
https://www.ebay.com/itm/Vintage-Rare-1 ... AOSwywRZ~z
Upon further searching I found this other ad with both Batman & Robin (3rd photo).