Claim: Oh Yeon-seo is a previous member of a band.

Rock band redirects here . For the video game series , see Rock Band . For the first game in the Rock Band series , see Rock Band -LRB- video game -RRB- . For the iOS version of same name , see Rock Band -LRB- iOS -RRB- .   A rock band or pop band is a small musical ensemble which performs rock music , pop music or a related genre . The four-piece band is the most common configuration in rock and pop music . Before the development of the electronic keyboard , the configuration was typically two guitarists -LRB- a lead guitarist and a rhythm guitarist , with one of them singing lead vocals -RRB- , a bassist , and a drummer -LRB- e.g. the Beatles , KISS , Franz Ferdinand -RRB- . Another common formation is a vocalist who does not play an instrument , electric guitarist , bass guitarist , and a drummer -LRB- e.g. the Who , the Monkees , Led Zeppelin , Queen , and U2 -RRB- . Instrumentally , these bands can be considered as trios .   The smallest ensemble that is commonly used in rock music is the trio format . Two-member rock and pop bands are relatively rare , because of the difficulty in providing all of the musical elements which are part of the rock or pop sound -LRB- vocals , chords , bass lines , and percussion or drumming -RRB- . In a hard rock or blues-rock band , or heavy metal rock group , a `` power trio '' format is often used , which consists of an electric guitar player , an electric bass guitar player and a drummer , and typically one or more of these musicians also sing -LRB- sometimes all three members will sing , e.g. Bee Gees or Alkaline Trio -RRB- . Some well-known power trios with the guitarist on lead vocals are the Jimi Hendrix Experience , Stevie Ray Vaughan and Double Trouble , Nirvana , the Jam , and ZZ Top .