This is an email i got after requesting info from citibank..
The man in the Citibank 'Ukulele' commercial is Graham Funke.
The song he sang is an origianal that he did for the commercial and Fallon
owns the rights to it. It has not been recorded for consumer distribution.
If you would like to contact Mr. Funke, his agent is Dragon Talent in LA.
Their # is: 323-653-0366. I do not know if he has other music available.
You could ask his agent that.
Thanks for your interest. Please let me know if you have further questions.