Born "Santo Gennaro" in Little Italy, (Manhattan's Lower East Side), Gennaro grew up on Staten Island, New York. At the age of 3 he showed interest in a toy drum and later at age 13 he played a friend's snare drum, which prompted him to buy his first drum set. At age 14 he joined his first band "The Black and Blues". Gennaro took private lessons and by 16 he was touring the New York/New Jersey/Pennsylvania circuit, playing high school dances, parties and minor musical events. At 18, Gennaro toured the Midwest playing night clubs and bars in a Cover band. In 1976 Gennaro moved to California and joined rock quartet Blackjack, featuring Michael Bolton, guitarist Bruce Kulick and bassist Jimmy Haslip. Blackjackrecorded two albums and toured with Peter Frampton which eventually led Gennaro to record his first hit single with the New York-based singer Benny Mardones, "Into the Night" and LP Never Run, Never Hide. This was the beginning of Gennaro's association with the Pat Travers Band and afterwards his connection with singer/songwriter Cyndi Lauper, whose debut album She's So Unusual became a multi-platinum hit. Lauper hired Gennaro for the Fun Tour as well as other national and international tours and he appears on the concert video for the singer's single "Money Changes Everything". From here Gennaro went on to record and tour with Bo Diddley, Joan Jett and Johnny Winter.
Gennaro frequently served as a counselor and teacher at David Fishof's Rock and Roll Fantasy Camps since 2007. Gennaro taught at The Collective in New York City for 27 years where he created the Music Business program, teaching private lessons and master classes before moving to Nashville.
Gennaro wrote several articles for Modern Drummer magazine. He is also the creator of "Drum Basics" and "Contemporary Rock Styles for the Drums."His writing is featured in the October 2016 issue of Drumhead Magazine (owned by Jonathan Mover) issue #057, page 70 "The Top 10 Straight 8th and 16th note Grooves Every Drummer Should know….And Why"