A panel of five judges will determine the winners of the 2009 Battle of the Bands. The judges represent a wide variety of music and experience in Tucson. They'll put their know-how to use as they vote on technical skills and competence, originality and creativity, entertainment value, songwriting ability and overall sound quality. The top three bands will be announced onstage at the end of the night.

Dan Twelker

Dan Twelker hosts "Locals Only" on 91.3-FM KXCI at 8 p.m. on Mondays. It features interviews and in-studio performances with Tucson bands and artists. He is also an optometrist for the University of Arizona's Department of Ophthalmology and Vision Science.

Dan Hernandez

Dan Hernandez got involved in the local music scene in 2001, designing and making prints and posters for bands. He managed hard-rock act Chango Malo on tour from 2002 to 2004. A graduate of Casa Grande Union High School, Hernandez is an entertainment booker at Club Congress.

Acorn Bcorn

Acorn Bcorn is a rock duo consisting of two sisters: Marina Cornelius on vocals and guitar, and Leann Cornelius on bass. (They also share drumming duties.) They were formerly two-thirds of the Beta Sweat. You can catch them at Plush on Feb. 28 with Lenguas Largas and Sic Alps. The duo recently recorded songs and will have a record out sometime in March.

Andrew Cox

Andrew Cox has managed bands for more than five years and co-owns DesertCore Management and Consulting. He was also the director of retail promotions for Century Media and Nuclear Blast Records, and he worked as a producer and engineer for Rose Studios in Clearwater, Fla. He is also a recruitment advertising sales representative at the Arizona Daily Star.

Mark Martinez

Mark Martinez is the operations manager for the Rialto Theatre. For the last eight years, he also has run his own business as a photographer specializing in music, mostly concerts. The Chicago native is an avid music fan, and he also worked in retail music as a store manager for more than 12 years.