Natalie"two-steps" out of the bathroom to the sound of "Hey Baby Que Paso," which the book describes as a "Tex-Mex" song she was particularly fond of. The song is playful, upbeat, and sung in Spanglish by the band Texas Tornados, many of whom are Anglo musicians. The accordion and steady drum beats are characteristic of some mariachi music but the keyboarding and slide guitar also give the tune a characteristic Texas ring.
Though the song sends a very different sentiment, "Wasted Days and Wasted Nights," is similar in it's Tex-Mex-ness in the sense that it is a slow, bluesy country ballad sung by a Tejano - Freddy Fender - in the typical style of a song-bird cantador. The song plays while Sway dances with Cal (who has always been sweet on her - in vain). This is an appropriate setting of place for this older, smokey dance hall full of younger women and older men who are looking for a good time on the weekend but not necessarily serious relationships. It also seems to place the Big-Five-Four in a bygone era - the song feels very much like a 50's country song even though it was sung in the 70's.
I think both songs communicate Natalie and Sway's "place" in they country/Tex-Mex, borderland of Lava Landing. The songs paint an audible picture of towns stuck in a time past and people stuck "wasting days and nights" intentionally. They are rather playful songs, but they also communicate the sense of longing that Martinez will continue to communicate throughout the novel for commitment and love.