McArthur Park has to be the worst song ever written. Even Donna Summer can't rescue the most strained metaphor in music history.
If you want easy go with Mellow Yellow by that old pervert, Donovan. It's in the exact middle of everyone's range, and contains about 3 different notes.
Just be sure to skip or talk over the second verse. There is a concert recording somewhere in which Donavan sings "I'm just mad about fourteen year old girls." Don't do that.