Well Cassidy's been playing drums since he was 10. He started private's with drummer Mike Chilton at age 11 acquiring a well-rounded musical style and caught on unusually quick.

At only 14 he was accepted to the New York, Drummer’s Collective, being introduced to many more styles of drumming and learning from some of the finest they have there in their Manhattan school. He returned home to Florida and continued his private's with Mike Chilton steadily, yet now added a weekly in depth class at Jeff Berlin's well-known Players School of Music. At the same time he played with jazz guitarist, Greg Smith, performed with Subdudes’ John Magney and various other performances, including impromptu shows in and about the streets of Tampa, Florida.

Well, when he was 15 he joined a 4-piece rock band, Plug and later another rock band led by talented guitarist and pianist, Yuri Obelinski.

Then at 17 he headed back to his birth place, Los Angeles to make some intense music with prog-rock band, Canon, which at the time was without a drummer and had their eye on Cassidy for a couple of years. Canon has played all over town since and has an incredible ensemble of musicians within itself.

Cassidy has continued to expand his skills with lessons from Woody Herman’s Chuck Flores, The Faunt School of Music’s Tom Mendola as well as Miles Davis’ Alfonze Mouson.

Still looking for more he hooked into the Hollywood’s Musician’s Institute(MI) program. Now here his drumming took a big leap with hints of jazz and Afro-Cuban into a progressive drumming style. Around this time he picked up the tenor saxophone and clarinet to gain a better understanding of music from a "real instrument" perspective. Mid 2005 he finished the MI Journeyman Level of the program. He now is exploring greater avenues of music and furthering his abilities on the drums as well as the sax and clarinet. He is extremely interested in and appreciates many styles of music. This guy is no dabbler. He is a true professional.

Cassidy teaches private instruction out of his studio in North Hollywood. He is continues playing all over and recording with prog-rock band, Canon. He continues to form and play in other projects and is available for studio work.