Dennis has been a musician since he was seven years old. After taking piano lessons for seven years, Dennis began performing in bands in 1964 after the Beatles came to America and topped the charts. The first band he was in was the Dimensions, based in Braintree, Massachusetts. Other Massachusetts bands were: The Miltones, The Young Ones, The Ryde, Cyrus Zain and State of Mind.

Dennis left Massachusetts to go to Medical School at Dartmouth Medical School (now Geisel School of Medicine at Dartmouth). While there he performed informally with local musicians, the most organized was a group of medical professionals called Balls and Fish. After graduating Medical School, he stayed on at Dartmouth-Hitchcock Medical Center to complete a residency in Internal Medicine. During that time, he performed in various café’s and restaurants with Priscilla Bolte in a duo called Out of Nowhere.

After leaving Dartmouth-Hitchcock, Dennis spend three years in the National Health Service Corps in Sandstone, MN during which time he performed in a trio rock and roll band called Prophet. On one occasion, Prophet was asked to do a one hour set of Beatles songs on the twentieth anniversary of the Beatles’ arrival in the United States as a fund raiser for the high school band. Halfway through the set, Dennis was called out to deliver a baby at the local hospital. Dennis ran out to the hospital, delivered the baby and was back at the high school to finish the last 30 minutes of the set! 

Dennis returned to New England to practice medicine, but continued to perform in bands, notably, Fascinatin’ Rhythm, a wedding and corporate party band. Also, He arranged and performed, along with Marguerite “Missy” Daniels, the theme song for a Cystic Fibrosis Charity Foundation called Karen’s Climb which was broadcast twice on NPR.

Dennis left New England to practice medicine in Minnesota. During that time he was the keyboard player for an R&B band named The Jagg, and a modern jazz band named Code d’Crie.

After leaving Minnesota and moving to the Hudson Valley, New York, Dennis sat in with several local bands ranging from a blues band to a wedding/corporate party band, although never a regular with any particular group. The next move was to Michigan where he was a founder and keyboardist in a local band called the Blues Infusion, whose personnel were all healthcare workers.

In 1999, Dennis moved to Albuquerque New Mexico. Since being in New Mexico, Dennis was the co-founder of a duo called Dragonfly with Veronica Saenz, which ran from 2004-2008, and the best classic oldies band in New Mexico, The 45’s, which ran from 2013 to 2018 and included Scott Carlson and Danielle Claypool. When that group disbanded, Dennis decided to learn how to play Jazz. He joined the New Mexico Jazz Workshop and attended weekly “Real Book Jam Sessions” in the fall of 2018. Since then he has performed with Jazz Breeze, The Lomas Street Jazz Band, and the High Desert Big Band. When the Coronavirus Pandemic hit and performing live was stopped, Dennis began composing jazz tunes and recording them in his home studio, Dragonflytunes Studio. In 2022 Dennis began releasing his composition in a series of album releases called “Virtually Jazz”.