There is more than one artist with this name:
1) Rosa is a four-piece folk punk band from Houston, Texas. Their latest release, I Mississippi You was released on Plan-It-X Records. Members
* Brad-acoustic guitar, vocals
* Emma Lee-snare, vocals
* Kirke-washtub bass, vocals, mandolin
* Ben-banjo, violin 2) Rosa Lopez, who performs and releases her music as Rosa, is a Spanish singer who won Operación Triunfo 1, a musical contest similar to American Idol.

Read more about Rosa on Last.fm.