SONG(S) OF THE WEEK: Jason Mraz's first single "The Remedy" was irritating as all get out, with its "you gots" and "I gots" faux folksiness and ooey-gooey chorus. However, his second single, "You and I Both," (Elektra) is elegant and uplifting, one of pop radio's current delights. Nick Lachey's first solo single, "Shut Up," was a frightening hodgepodge of bad dance music cliches. His second single, "This I Swear" (Universal), the theme song on MTV's "The Newlyweds," is sweet and simple, allowing his inner balladeer to take its star turn. Music moguls, take note: Second chances are important. So could someone please give Justin Guarini a hug? Thanks.