Which song(s) was the ice cream truck playing (audio clips in each link)?
That's a really fun set of links; I enjoyed playing them, thanks!

By the way, I'd never heard the original version of Camptown Races before; to most English people, it's undoubtedly better known with the lyrics used in the chant during any England-Germany football game: "Two World Wars and One World Cup, doo dah, doo dah..."
The less sung second chorus is the even more charming "My grandad killed your grandad, doo dah, doo dah..." Got to love those chants.

In the UK we have a whole different set of jingles on ice cream vans. Common ones I remember were Greensleeves, O Sole Mio (largely because of the Just One Cornetto ad), Yankee Doodle (won't bother linking to that one, but did you know it was actually originally a Royalist song mocking Oliver Cromwell?), Bicycle Made for Two, The Sun Has Got His Hat On, and I think I've heard Match of the Day a few times too.