Clementina!

I don't know if this is apocryphal or not but that machine was supposedly named Clementina because it could 'play' part of "Oh my Darling, Clementine".

Found this cool video doing a little sampling but I have yet to find a sample of a Ferranti Mercury playing the tune. https://youtu.be/CiEw5kmRvvs?t=45

Edit: Here are some engineers playing games with 'her': https://toobnix.org/w/3doJWfhE3H1D5oVg2DYQQJ