Linda Ronstadt

The film, chronicling the famed singer's life, is due in September.

She ended up working with some of music's biggest names, transforming many of their songs into her own.

It took a little bit of blind luck for the singer's first-ever concert recording to see the light of day.

She initially gained national exposure while singing backup on "Heart of Gold," the chart-topping single from 1972's 'Harvest.'