Cher has employed various musical styles, including folk rock, pop rock, power ballads, disco, new wave music, rock music, punk rock, arena rock, and hip hop; she said she has done this to "remain relevant and do work that strikes a chord". Her music has mainly dealt with themes of heartbreak, independence, and self-empowerment for women; by doing so, she became "a brokenhearted symbol of a strong but decidedly single woman", according to "Out" magazine's Judy Wieder. "Goldmine" magazine's Phill Marder credited Cher's "nearly flawless" song selection as what made her a notorious rock singer; while several of her early songs were penned by or sung with Sonny Bono, most of her solo successes, which outnumbered Sonny and Cher's successes, were composed by independent songwriters, selected by Cher. "Not.com.mercial" (2000), Cher's first album mostly written by herself, presents a "1970s singer-songwriter feel" that proves "Cher adept in the role of storyteller", according to AllMusic's Jose F. Promis.