Compás literally translates to "compass" (the drawing tool) or "measure" (in music). In this song, it refers to the musical "beat" or "rhythm" that guides the music.
Paulina Rubio sings, "Mi corazón, y sus latidos, Siguen el ritmo que les marca tu compás" (My heart, and its beats, Follow the rhythm that your beat marks for them). It's an interesting word because while it can mean a compass, in a musical context, it beautifully describes the guiding rhythm of a song, and here, the rhythm of a loved one's presence.
Paulina Rubio recorded 'Vive el Verano' for her 2000 album Paulina, timed to the turn of the millennium: the opening lines promise 'Con el 2000 que está llegando' [With the 2000 that's coming] and 'Este verano lo recordarás así' [This summer you'll remember it like this]. From there it's a straight instruction to dance — 'Mi corazón, y sus latidos, siguen el ritmo que les marca tu compás' [My heart, and its beats, follow the rhythm your beat sets], moving through 'salsa hip-hop, música disco' [salsa hip-hop, disco music] because, as she sings, 'Nos da lo mismo, lo importante es no parar' [It doesn't matter to us, the important thing is not to stop]. The chorus repeats one line on loop: 'Baila, baila mi vida, dame calor' [Dance, dance my life, give me heat].