springfield missouri hq. >> i was a geek before there were geeks. >> robert and his team tore these machines apart to learn what makes them tick and click and clack. this one used to wrap cigarettes in the 1930s. now it wraps cassettes. you can't learn this stuff in school. >> no. you don't learn this in school. you learn this in school hard knocks. >> and it's the young and up and coming independent musicians who are driving the newfound demand. >> digital streaming is short-term whereas a cassette is the exact opposite. it's tangible. >> rewinding the way we listen to music has fast forwarded one company to the top of the charts. kevin tibbles, nbc news, springfield, missouri. >> when we come back, what you need to know to keep your small business from being audited by