Last week Rock Daily reported that the next Hear Music signing would be "one of the all-time great female artists." Today, Starbucks' label made it official, announcing Joni Mitchell will join the label following the success of its first major star, Paul McCartney, whose Memory Almost Full generated 47 percent of its sales in Starbucks stores. Mitchell's first Hear Music album is actually her third effort with the Seattle-based company -- she has released one compilation of her favorite music and another where artists like Elvis Costello and Bob Dylan chose their favorite tracks of hers. The forthcoming Shine will hit stores on September 25 and is a part of a series of new work that includes a ballet and an art exhibit. It is also Mitchell's first album of new material since 1998, and she describes it as "as serious a work as I've ever done."