When our two eldest were small they were very fond of "Fish Heads" orginally put out by Barnes and Barnes as well as an older song about "You put the lime in the cocoanut and drink it all up". Then again, we both sing and now they do, too, and things can get a bit eccentric with a 15 y.o. boy doing the "Major General's Song" from The Pirates of Penzance
Just a a side note, he is in his high school production of "High School Musical 2" and it's been ummm an adventure. He's in it for the experience, not because he has a fondness for the HSM series. (Two months ago he was in the ensemble for "Les Miserables" and got to wave the banner on the barricades). Though from what I understand, while it's teenagers singing and dancing, it's rather more innocent and happy endings.