Simplify the following text for a Grade 10 native English-speaking person.
Original: The Coachella Valley Music and Arts Festival ( commonly known as Coachella or Coachella Festival ) is a three-day ( formerly a one or two-day ) annual music and arts festival , organized by Goldenvoice ( a subsidiary of AEG Live ) and held at the Empire Polo Fields in Indio , California , in the Inland Empire 's Coachella Valley .
Simplified: Coachella Valley Music and Arts Festival , best known as just Coachella , is an annual three-day music festival held in Indio , California .