Melissa Etheridge [ tickets ] has filled in some of the remaining few gaps in what already was shaping up to be a lengthy summer tour, as the singer/songwriter prepares for her first outing since undergoing successful treatment for cancer.

Etheridge has added new stops in California, including two nights in Long Beach, as well as a trio of Texas engagements; she'll visit Austin July 14, followed by shows in Dallas and Houston.

Tickets for all shows on the tour, including the newly added dates, are on sale now. Details are included below.

Etheridge is touring in support of "Greatest Hits: The Road Less Traveled," which hit stores in October.

Earlier this month, Etheridge announced via her website that her partner Tammy is pregnant with twins. The couple used an anonymous donor from a bank, according to Etheridge, who has two children--both genetically fathered by David Crosby--from her previous relationship with Julie Cypher.

In 2004, Etheridge underwent two cancer surgeries, during which a tumor and some lymph nodes were removed from her breast. Her first public performance following the surgery took place at 2005's Grammy Awards ceremony, where the singer--bald after undergoing chemotherapy--and fellow vocalist Joss Stone sang a tribute to the late Janis Joplin.

Etheridge announced in August of last year that she was "totally cancer free."