This harmonica [minus the keychain] is identical to the one which was the first musical instrument to be played in space. Astronaut Walter M. Schirra played "Jingle Bells" on his Hohner #39 "Little Lady" on the Gemini VI Mission, on December 16, 1965. He was accompanied by astronaut Thomas P. Stafford, Jr. on the jingle bells. Schirra's harmonica and Stafford's jingle bells are now on display at the National Air and Space Museum, Smithsonian Institution, Washington, D.C.
It was in the gift shop there that I bought my first Hohner Little Lady, for $3.50 -- a long time ago! I taught myself to play "Jingle Bells" and "Joy to the World" on it. It comes out of storage every Christmas, and when I'm not playing it, it hangs as a decoration on the Christmas tree, next to a set of tiny jingle bells on a string.