Mr. Guo said his drive to create a grand repository of music stemmed from his childhood in China, where his parents, both engineers, sent him to study violin at the elementary school of the Shanghai Conservatory. Browsing through a bookstore one day, he said, he was frustrated by how few orchestral scores were available. His father took him to Vancouver, British Columbia, for high school when he was 13. Mr. Guo graduated a year early and entered the New England Conservatory of Music in Boston to study composition. There a world of scores, at the library and in music shops, lay open to him. But the memory of musical deprivation remained strong, and the idea of a bank of digital scores took flight.