Tonight, Cake is returning to St. Louis with a sold-out show at the Pageant. Last week, we printed an interview with multi-instrumentalist Vince DiFiore, in which writer Ryan Wasoba discussed the band's frequent use of an instrument called the vibraslap. What is that, exactly? Well, the inaugural edition of the RFT's (soon-to-be-recurring) music lessons will educate, enlighten and inform. Read on below: