As Sergio Mendes's Timeless demonstrates, the songwriting of Brazilian masters like Antonio Carlos Jobim, Baden Powell, and Jorge Ben is like architecture that retains its beauty under the weight of any addition. So while Black Eyed Peas producer will.i.am might not add any real elegance to compositions like "Surfboard" and "Mas Que Nada," his hip-hop beats combine with Mendes's jazzy keyboards for a mostly satisfying update of a classic pop style. Timeless boasts an impressive array of guest stars, from Stevie Wonder (a harmonica turn on Powell's "Berimbau/Consolação") to Q-Tip and Brazilian rapper Marcelo D2. All acquit themselves well, although lyrics like "Brazilian beauties with booties that wobble" don't stretch their abilities. But "Loose Ends," featuring Justin Timberlake, forgoes booties for political commentary that mentions gas prices and Tomahawk missiles, all wrapped in elegant music that suggests a synthesis of Mendes's great 1992 Brasileiro and Marvin Gaye's What's Going On.