Final answer:
Mussorgsky did not write Pictures at an Exhibition as a ten-movement piano suite in twenty days.
Step-by-step explanation:
No, the statement is false. Mussorgsky did write Pictures at an Exhibition as a ten-movement piano suite, but he did not complete it in twenty days. The composition process for Pictures at an Exhibition took place over a longer period of time. Mussorgsky started composing the suite in 1874, inspired by a memorial exhibition for his friend Viktor Hartmann. It wasn't until 1875 that Mussorgsky completed the composition. So, the correct answer is False.