"Corbie" means "crow" in Scots, but "crow" usually means "rook".
It's "three crows sat upon a wall", completely different song. "Three Ravens" is the one that's the same family as "Twa Corbies".
An entirely unrelated tune:
X:362
T:Da Corbie an' da Craw
B:Ringing Strings, Tom Anderson (Lerwick 1983)
Z:Nigel Gatherer
L:1/4
M:4/4
K:D
B|A2FD E2=c2|EFGE =CDEC|DDFD E2 =c2|EFGE [G,3D3]:|
F|AddA d2 df|efec d2FA|A,dd>c d2 eg|f>de>c d2 AF |
Addc d2 df|efec d2FA|dB=cA B2 Gc|E>FG>E [G,3D3]|]
I just remembered the author of that parody - the Rev. Alexander "Jupiter" Carlyle of Inveresk, who was something like the chaplain of the Scottish Enlightenment.