The Nissitissit String Quartet was officially formed in 2019, although we have been working together in different forms for many years. We love performing live music and bringing meaningful performances to our home communities!

About the Musicians: 

Ayer’s Lisa Kempskie has a degree in violin performance from UMass Lowell and has done graduate work in music education at the University of Connecticut at Storrs. Equally comfortable on violin and viola, she freelances throughout the greater Boston area and is currently principal viola of the Lexington Symphony. For 7 years, Lisa directed the elementary and middle school string program in the Winchester Public Schools and is currently on the faculty of the Westford Suzuki School. She also has studied bow-making, repair, and rehair at the Violin Craftsmanship Institute in New Hampshire, and works as a repair person for regional string companies as well as many local players. Lisa is a certified music practitioner through the Music for Healing and Transition Program which trains musicians to aid the sick and terminally ill through individually-tailored live therapeutic music.

Pepperell’s Peter Stickel was concertmaster of the Bucknell University orchestra. During graduate work in music therapy, he studied violin with George Zazofsky, former assistant concertmaster of the Boston Symphony Orchestra. Peter performed in a variety of venues before founding New England String Ensemble with John Bumstead and becoming its executive director for the next 15 years. During that time and since he has performed in many orchestras, with touring star attractions, such as Johnny Mathis, Smokey Robinson and Josh Groban, and in show orchestras, including at New Repertory Theatre, Emerson Stage, SpeakEasy Stage and Stoneham Theatre. Since 2011 he has been the violinist for the New England Tenors.

Dunstable’s Valerie Callahan has been teaching and performing on the violin and viola since childhood. She studied violin with Geda Khatutskaya of the New England Conservatory, and attended UMass Lowell, earning her Bachelor's in Music Education under the tutelage of Anne Black on the viola. She has a Master's in String Performance on viola from the Boston Conservatory, where she studied with Patricia McCarty of the Boston Symphony Orchestra. She previously performed with the Concord Orchestra, New Hampshire Philharmonic and the Civic Symphony of Boston. She taught private lessons for 8 years at Groton Hill and 20 years at the Westford Suzuki School, and was a co-founder of Bridges and Bows in Westford. Valerie is currently a member of the music department faculty in the Dracut Public Schools, leading string instruction and orchestras for grades 4-12. 

Pepperell’s John Bumstead co-founded the New England String Ensemble and was a 17-year member of its cello section. His music education includes undergraduate studies at Baldwin-Wallace Conservatory in Ohio and Manhattan School of Music as well as a Master of Music degree from the University of Massachusetts - Lowell. Major teachers included Regina Mushabac, David Finch, and Frederick Zlotkin, as well as chamber music studies with Lillian Fuchs. He is an active freelance musician in the Boston area, including regular performing with Symphony by the Sea and at North Shore Music Theater. In addition to his private studio, John is cello professor at UMass, Lowell where he performs in a faculty piano trio.