After leaving a professional career as a violinist, Jonathan worked with René A. Morel and later partnered with Florian Leonhard. His understanding of sound, gained through years of professional training and performance practice, combined with his knowledge and experience with string quartet family instruments and bows, has major musicians from across the globe seeking his assistance in their searches.

Jonathan began his studies on the violin at a young age, and his love for fine stringed instruments was evident early on. At 18, he started his studies at the Oberlin Conservatory of Music where he studied violin, baroque violin, and viola, eventually graduating with a degree in Violin Performance.

In 2004, Jonathan moved to New York City to pursue his passion for violins and, in 2005, became Sales Manager for René A. Morel. Jonathan has a proven track record of success in building collections and being a global leader in the sale of historically important instruments, starting with his experience with René A. Morel and culminating in his partnership with Florian Leonhard in 2014.

Today, he operates a boutique in New York City with his wife, violinist Katie Thomas. He holds the distinction of being one of only three Certified Members of the Appraisers Association of America in his field globally and is also a Board Member of the Elevar Foundation and the International Contemporary Ensemble.

Professional Freelance Violinist, Chamber Musician, and Soloist, Katie Thomas has performed widely throughout the major venues in NYC and has been a soloist with orchestras internationally. She won a Grammy Award for her work with Sarah Jarosz on her album World on the Ground. Katie is always happy to lend an ear to anyone needing her expertise with their search.

“Just left of downstage center, one musician...Katherine Thomas, focusing the sound of the orchestra, fighting the tide, and delivering solo phrase after solo phrase with thoughtful integrity enough for a Brahms Concerto...”

Astonishing audiences with her musical vitality, Katie Thomas brings incredible confidence, versatility, and artistry to her performances. Her work attracts both critical and professional praise and reflects her adaptability as a soloist, chamber musician, studio violinist, and as a leading orchestral musician.

Katie won a Grammy for her work for Sarah Jarosz’s award-winning album World On The Ground. She has additionally recorded with artists Rosanne Cash, Jimmy Fallon, Bebe Rexha, Lewis Capaldi, James Arthur, Norah Jones, and John Legend. She has also performed in NYC’s Radio City Music Hall Christmas Spectacular with the Radio City Rockettes and regularly appears in Broadway’s Tony Award-winning hit, Hamilton. Katie holds both undergraduate and graduate degrees from the Manhattan School of Music, where she studied with Lucie Robert.

Sam Morel serves as Head of Conservation and Restoration at Jonathan Solars Fine Violins, Inc., overseeing the long-term care, documentation, and responsible treatment of fine stringed instruments and bows.

Sam’s training began early: at 17, he became France’s youngest violin-making student, entering the craft through an apprenticeship with Nelly Poidevin in Dinan, before attending the Lycée Jean-Baptiste Vuillaume in Mirecourt.

He approaches restoration with a disciplined, materials-first methodology—prioritizing stability, playability, and respect for original surfaces and workmanship. Sam’s work ranges from precision setup and adjustments to complex restoration and varnish retouch, supported by careful documentation and clear condition reporting. He is also a trusted partner in client consultations, offering discreet guidance for performance needs, acquisitions, and collection care.

Prior to joining the firm, he spent five years at Finlay & Gage in New York. His work has earned a Violin Society of America Certificate of Merit (2018) and a Silver Medal for Tone at the International Society of Bassists Makers Competition (2019).

Violinist Miguel Calleja brings a distinctly international perspective and a deep understanding of the performing musician’s experience to his role as Client Advisor at Jonathan Solars Fine Violins. Described by composer Gabriela Lena Frank as “a money musician, a virtuoso,” Miguel has built a multifaceted career as a performer, educator, and advocate for contemporary music, with engagements throughout Europe and the Americas. His experience across a broad range of musical traditions informs his approach to helping musicians discover instruments that complement their individual artistic identities and aspirations.

A member of Orange Road, a string quartet dedicated to contemporary repertoire, Miguel has appeared at Duke University, the University of Florida, the Mannes Chamber Music Festival, and the Gabriela Lena Frank Creative Academy of Music, among other prominent venues and festivals. His collaborations with composers including Augusta Read Thomas and Michael Riesman reflect a particular interest in the relationship between performers and the creative process. In 2025, he performed Philip Glass’s First Violin Concerto in Spain, while his work as an educator has included workshops at the Royal Conservatory of Music in Granada and lecture-recitals exploring Spanish musical traditions at institutions in both Europe and the United States.

Miguel’s artistic interests extend beyond the classical concert stage, encompassing collaborations with musicians and artists working in flamenco, popular, and traditional music. He has also participated in Violins of Hope, an initiative dedicated to preserving the stories of instruments that survived the Holocaust. He studied violin and musicology in Spain and the United States, working with teachers including Biljana Belloti, Eva Szekely, and Ari Streisfeld.

At Jonathan Solars Fine Violins, Miguel draws upon his experience as a performer and his understanding of the personal relationship between musicians and their instruments to guide clients through the process of selection and acquisition. Working closely with Jonathan and the firm’s restoration and expertise team, he is committed to cultivating lasting relationships with musicians, educators, and collectors, bringing an artist’s sensitivity and a thoughtful, individualized approach to every engagement.