Non-specific Citrus-Berry Punch

You know how Froot Loops don’t taste like any actual fruit known to man?  They kind of actually taste like some kind of non-specific citrus/berry thing?  Well, after taking my first sip of this drink, I had the exact same reaction.

1 shot rum (preferably white rum, like Bacardi)
4 oz Raspberry soda
fill the rest of a 8oz tumbler with equal parts grape juice and lemonade
serve on the rocks