Or we use binary to write all bases, since binary is the simplest. So English uses base 1010, and the alien is using base 100.
This system does break down when trying to use a base that isn't a positive integer. I've heard of people trying to use base e (yes, as in euler's number) for maths research.
Going on with your songs theme, in "Shotgun" by George Ezra, right at the start of the second verse, it sounds like he burps. It's "brrrppsouth of the equator"