Final answer:
The Moscow production of 'P and G' is not specifically identifiable, but famous Russian composers of the Moscow arts scene during the Soviet era included Sergei Prokofiev, Dmitri Shostakovich, Aram Khachaturian, and Rodion Shchedrin.
Step-by-step explanation:
The question refers to the Moscow production of P and G, which is likely shorthand for a theatrical or musical work that was seen by a famous composer. Without further context, it's difficult to provide a specific answer to which production this refers to and the famous composer who saw it. However, we can discuss the Moscow arts scene during the era of Soviet power and the composers who were active during this time.
Notable figures include Sergei Prokofiev, a renowned composer who returned to Soviet Russia after a period abroad; Dmitri Shostakovich, another major Russian composer known for his complex and challenging works; Aram Khachaturian, remembered for compositions like Spartacus and Gayane; and Rodion Shchedrin, who rose to prominence in the mid-20th century.
Of these composers, Khachaturian was mentioned in conjunction with 'A song about Stalin' in one of the provided references, which might indicate his presence in Moscow during relevant productions.