I think I'll go for ye olde augmented chord...
I'm a bit sloshed, like....so I'm not even sure what it is
This is maybe my favourite song...I often play it just with an acoustic guitar...I haven't really heard a version that is perfect...but, despite it being over 100 years old...I love it... loads of different versions in different keys...but I got stuck in Eb...
...and there's a bit where (I think) it goes
Cm Gm
I would say such wonderful things to you
Ab - Ab+ - Bb - Bb+ - Eb - Bbm - C7
There would be such wonderful things to do
Fm Abm Eb C+
if you were the only girl in the world.........................................
F7 - Bb7 - Eb
and I were the only boy
my favourite version is by Stanley Holloway...who I always thought looked a bit like my mams brothers Charlie and Archie (deceased)