Final answer:
Johann Sebastian Bach originally composed pieces for orchestra that have been arranged for two guitars, highlighting his signature baroque style and melodic counterpoint.
Step-by-step explanation:
The composer who originally composed his piece for orchestra but has an arrangement for two guitars is Johann Sebastian Bach.
Bach's compositions are frequently transcribed for different instruments, and many of his orchestral pieces have arrangements for guitar duos.
While Arnold Schoenberg was an innovator in atonal music and the twelve-tone scale, Bach was known for his Baroque compositions that adhere to the scales and harmonic expectations of Western music.
Two guitars performing a Bach piece can bring out the counterpoint and harmonic intricacies that characterize his music.