Final answer:
Johann Sebastian Bach might have been seen as ordinary in his time compared to other progressive composers due to his adherence to Baroque styles and less emphasis on innovation in form, which contrasted with later composers who pushed musical boundaries catered to a burgeoning middle class audience.
Step-by-step explanation:
During his time, Johann Sebastian Bach might have seemed ordinary when compared to other famous musicians and composers because of the differing social, technological, and artistic contexts. As music evolved, composers like Berlioz, Strauss, and Wagner emerged as progressives who stretched the boundaries of music and challenged their audiences with new styles and forms, whereas Bach, with his intricate counterpoint and complex harmonies, was seen as a master of the established Baroque style rather than an innovator of new musical forms. Another aspect was the rise of the middle class and the shift from music being a patronage-based form of entertainment for the upper-class to something that was part of large public concerts and festivals.
Moreover, Arnold Schoenberg's atonal music and twelve-tone scale were radical departures from traditional western music, which would have made the works of Bach seem conventional in comparison. The invention of the Gutenberg press greatly expanded the distribution of music and raised the demand for new musical entertainment, which facilitated the mass dissemination of new styles and the rise of the Romantic movement, with composers like Brahms, Tchaikovsky, and Wagner taking the spotlight with their emotionally expressive works. Yet, it's important to revisit Bach's music not for the novelty or shock it may lack but for the deep musicality and mastery it showcases.