Halloween "Silver Shamrock" Tune Melody

[Petrus]

I'm trying to get this addictive melody, from the fictional Silver Shamrock company commercial in the movie Halloween III, down for an upcoming Halloween party. As of now I've got C-D-C-A-A#-C-D / F-C-A-F. The FCAF is for the "sil-ver sham-rock" that ends the melody. That's with a low F, coming back up to the C and A. But somehow the final F (with the "-rock" syllable) doesn't sound right. Suggestions?

[Bill Snyder]

You must be playing it a different key than the video. The tune is London Bridge is Falling Down and in the video the first note of the melody is a D not a C.
DEDCBCDABCBCDDEDCBCDADBG then BCDGACBABG.

[Petrus]

Thanks. I didn't recognize it at all! And yeah, I'm going a few octaves below that falsetto on my emandolabass.

[Marty Jacobson]

Oh, that's where you went wrong. You're supposed to play it on an esopranomandocello.