Few bands have a back story as improbable as ESG's. The 20-year-old minimalist funk group originally consisted of four Puerto Rican girls from the Bronx, the Scroggins sisters, and one of their neighbors, percussionist Tito Libran. When the Scrogginses were teenagers, their mother bought them instruments--a guitar for Renee, a drum set for Valerie, a bass for Deborah, and congas for Marie--hoping they would develop a hobby to keep them off the streets; within a few years their stripped-down, intuitive music would find a home at the nexus of punk, funk, hip-hop, and house. On the recent retrospective ESG: A South Bronx Story (Universal Sound), the almost primitive simplicity of the group's deep grooves gives them a broad appeal; Renee half sings, half speaks with charming sass, crafting subtle pop hooks--from the spacey melody of the protohouse classic "Moody" to the girl-group panache of "My Love for You"--that belie her casual, offhand delivery. ESG's formal career began in 1981, when Ed Bahlman, who ran the influential label 99 Records--home to Glenn Branca, the Bush Tetras, and Y Pants, among others--discovered the band at a talent show. Alongside the horn-stoked funk group Konk and 99 labelmates Liquid Liquid, ESG was part of a clique tangentially related to New York's no-wave scene, providing a danceable version of its crude, neurotic austerity. Within a year the band had cut a seven-inch EP, released by 99 and the British label Factory and produced by Joy Division standby Martin Hannett; one of those songs, "UFO," has since been sampled by countless hip-hop acts, including Public Enemy, TLC, and Doug E. Fresh. The sisters claim they never saw a dime from their 99 recordings--in 1993 they released a single called "Sample Credits Don't Pay Our Bills"--and it couldn't have helped that the label bankrupted itself suing Sugar Hill Records (Grandmaster Flash had swiped the bass line from Liquid Liquid's "Cavern" for his "White Lines"). ESG's current lineup includes Valerie and Renee's daughters, and though most of the band's more recent stuff doesn't measure up to the classic material, this ultrarare performance--part of Ladyfest Midwest (see sidebar)--shouldn't be missed. Saturday, August 18, 8 PM, Congress Theater, 2135 N. Milwaukee; 773-252-4000.