Callahan Piano Service is a family-owned and operated piano tuning and repair company in Oakland that has been in business for almost 50 years. The company was featured in Oscar® winner John Korty’s documentary Miracle in a Box. Owner John Callahan is a member of the Piano Technicians Guild. The company has more than 6,000 customers, including churches, recital halls, and recording studios, and has become the largest piano service organization in the Bay Area. The company’s services include tuning, voicing, refinishing, and reconditioning pianos.