with zyrtec ® i can love the air ™ . s >>> back in the '50s they had so many hit records together les paul and mary ford. les paul played at this jazz club in new york city talked to people who have seen him, and he was amazing. >> there's quite a bit of controversy, but he's widely credited for inventing the electric guitar. this guy had patents galore. people still, as they embark on careers, remember their first les paul. >> what about tape delay? multi-back recording, changed the recording industry. >> and my contention is there's no woodstock, per se jimi hendrix playing the national anthem on an electric guitar without les paul. >>> tomorrow marks four decades since nearly 500,000 people descended on a farm in upstate new york for an event called woodstock. it was an event that unexpectedly made history and defined a generation. it was a time filled with anger and confusion. there were wars, riots, and revolutions. and a generation searching for its identity. >> it wasn't a generation gap. it was a generation chasm, kids against their own parents, police against kids. >> for this generation music was their refuge. ♪♪ the farm in upstate new york wo