Christina Aguilera Back to Basics (RCA) Why over-sing when she has a naturally strong voice? Why blow her own trumpet when fans will eventually make up their own minds? For Christina Aguilera, the mistakes are magnified because Back to Basics, her first album in four years, offers 22 tracks over two discs. Like many double albums, there are some duds among the mediocre and the good. Which means finding songs worth listening to requires wandering through a mirrored maze that replicates flaws. To make matters worse, the extended jazz, funk and R&B playlist includes self-congratulatory introductions that only underscore what she's not: 'The one and only'? What about Pink or Beyonce? 'There will never be another...'? See previous comment. Her strategy in valuing quantity over quality led to the employment of two producers: DJ Premier, who was responsible for much of the sample-heavy, club-friendly first disc, and Linda Perry, who placed Aguilera in jazzy 30s, 40s and 50s settings and had her parody past starlets. Highlights are Ain't No Other Man and Makes Me Wanna Pray (featuring Steve Winwood), one of the few tracks that places Aguilera on the dais with her idol Aretha Franklin, albeit on a lower step. Equivalents on the Perry disc include the tarty Candyman and the quiet Save Me From Myself, in which Aguilera stops shouting songs and singing tunes. To quote her: 'Well everybody got an opinion now, don't they.' That may appear to be a defiant response to naysayers, but it can also be read as an admission of guilt. On Here to Stay, she promises to be 'steppin' it up', when what she really should be doing is taking a step back. Maybe then she would learn the meaning of less is more.