original_query: What is John Sebastian known for in the music industry?
query: What is John Sebastian Sr. known for in the music industry?
answer: John Sebastian Sr. is known as a master of the classical chromatic harmonica. He was the first harmonicist to adopt an all-classical repertoire and helped establish the harmonica as a serious classical instrument. He transcribed classical works for the harmonica, composed his own works, and commissioned others to write for the instrument.