Unlike the majority of teen-dream music acts, who are usually made to order to the specifications of some mad marketing Svengali, the three brothers from Tulsa, Okla. were an actual band before hooking up with the industry pros who guided them to stardom. That much and more was apparent at Hanson's SRO Chicago-area appearance, July 31 at the New World Music Theatre in Tinley Park, Ill. Their every gesture brought forth waves of shrieks from the legions of mostly pre-pubescent girls in blissful attendance, but the hysteria was, to a large degree, merited. Hanson's ultra-infectious bubble-rock wasn't exactly challenging, but as light entertainment it was undeniably satisfying.

No doubt everyone's heard the Hanson saga by now, about how the home-schooled brothers (three of seven siblings) got the bulk of their rock'n'roll education from Time Life compilations of `50s-`60s pop and soul, and are now knocking out their own `90s version of same. Then there's the part where Isaac, Taylor and Zac Hanson practically had to beg for attention at annual music-biz conclave South by Southwest in Austin, Texas a couple of years ago, by playing on street corners. Now the threesome's one of the biggest bands in existence, and in Tinley Park, they put on a show that justified those millions of Hanson posters taped on pink-flowered bedroom walls around the globe.

Middle bro Taylor, 15, whose gem of a Michael-Jackson-circa-1970 voice has deepened, gotten grittier and even more soulful, provided the most obvious visual focal point behind his Kurzweil keyboard. Taylor's impassioned vocalizing was riveting, but big brother Isaac, Hanson's 17-year-old guitarist, exhibited a confidence and ease that held down his end of the stage as well. Drummer Zac, 12 -- what could be seen of him behind his kit -- capably anchored the ensemble, which also included an unobtrusive backup guitarist, bassist and keyboardist (each of whom were given, democratically, a short solo late in the set).

Mixing their own winsome material -- "Man From Milwaukee," "Thinking of You," "Where's The Love," their crown jewel "MMMbop" -- with covers of soul classics like "Gimme Some Lovin'," the boys delivered a smoothly paced set punctuated by a short acoustic interlude midway through. It was especially then that it was evident to devotees and nonbelievers alike that the brothers Hanson, harmonizing sweetly with no visible technical support, really can deliver the goods. (Moira McCormick with Lily Espinoza)