sentences:  Together they made more than a dozen promotional films documenting artists including Ry Cooder, Joni Mitchell, Randy Newman, Earth, Wind & Fire, and Captain Beefheart.They were by nature documentary films, which could be rented or bought by any accredited music school.Parks later described the department as "promotional—but they could create an income stream for musicians who were hard-pushed into tours that required drugs to sustain them."