With its still-vibrant animation and unforgettable earworms, “SchoolHouse Rock!” turned 50 this year, having taught Generation X and subsequent youth math, history and grammar. Today, the series’ 1973 debut also serves as a lesson in nostalgia, “a reminder of a time when network TV gave us a common culture, language and lyrics,” writes The New York Times’ chief television critic James Poniewozik. Poniewozik joins us to talk about the groundbreaking TV show’s role in a shared civic education. And we’re inviting you to join us on our train ride to conjunction junction: Sing a few bars of your favorite “SchoolHouse Rock!” song and tell us what the show means to you on our voicemail line: 415-553-3300.Guests:James Poniewozik, chief television critic, The New York TimesHaydee Rodriguez , History and English teacher at Central Union High School, Imperial County