It's the guitar melodies that are front and center on Random Walk, not the vocals, which provide more of a blunt edge to sharpen the sound of the guitars, like on "Margaret With Comets," where the pop riff is made even more infectious when combined with the messy sing-song vocals. Which is not to say that the vocals and lyrics should be ignored entirely: "Reckless" perfectly addresses Tucson's oppressive monotony of sunlight, and "Bathmat Song" builds on a metaphor of bathwater spilling over.
But it's not just the vocals that help those guitar melodies stand out. When they are accented by other instruments, like horns on "Unravel" or keyboards on "Bathmat Song," they become even catchier.
The record ends with "Piles on the Floor," perhaps the best achievement on the record. The contrapuntal guitar and bass melodies heighten that guitar sound that The Swim's been reveling in for the whole record, taking it to another level.