Elvis Costello might dabble outside the rock world, but he's no dilettante. His early experiments in country and soul revealed an almost academic, but clearly passionate, interest in popular music. In the years preceding his Burt Bacharach partnership, Costello honed his never-smooth voice into an instrument at least moderately capable of delivering the complex melodies he helped write. In preparation for his collaboration with The Brodsky Quartet, Costello even learned Italian notation and how to read music. While all this study of songcraft seems to have buried for good the Angry Young Man persona of his past, it has resulted in some surprises, especially since he's paired his quest for personal improvement with an ongoing attempt to work with every one of his musical heroes. For The Stars, which pairs Costello with Swedish mezzo-soprano Anne Sofie von Otter, may be one of the biggest jaw-droppers of his career, but it makes sense considering his broad tastes. A longtime fan, Costello once wrote a suite of songs for the singer to tackle during her own Brodsky Quartet outing. Years later, he made good on his promise to work with her again, in typical overkill fashion. For The Stars boasts a fine selection of songs chosen by Costello, including a few of his own and a handful of new compositions, and not only did he produce the disc and play along, but he also dared to sing a few times. As shocking as it may be to hear him alongside von Otter on "Green Song" and the title track, it's even more interesting to hear a classically trained singer handling esoteric works by the likes of Tom Waits, Ron Sexsmith, The Beach Boys, Beatles, ABBA, and Kate McGarrigle. Von Otter's renditions of Brian Wilson's Pet Sounds masterworks "Don't Talk (Put Your Head On My Shoulder)" and "You Still Believe In Me" are stunning, while Sexsmith's "April After All" suits her soaring voice perfectly. The strange but oddly sensible medley of Waits' "Broken Bicycles" and Paul McCartney's "Junk" works amazingly well, even incorporating some accordion from another of Costello's unlikely heroes, ABBA's Benny Andersson. For The Stars could have been a disaster, but credit Costello with much of its success. He keeps the chamber-pop/jazz arrangements subtle, letting von Otter glide above the quiet, graceful music and allowing Sweden's creative Fleshquartet space to shine. A pleasant diversion that proves remarkably powerful, For The Stars is one of the best pop-classical crossover albums ever made, though listeners will have to determine for themselves which way the disc leans. The best way to circumvent the problem of where to file it is to simply keep it by the player, where it'll no doubt end up anyway.