Late 1800 early1900
Mussorgsky belonged to the Romantic period.
1929-1988
It was passed in 1920.
He was a composer during the Romantic era.
That is called "anachronism," where something from one time period is placed or shown in another time period where it does not belong.
Period 4
Classical period
It depends on how you want to define "time period". It belongs to the modern age, the 20th and 21st centuries, the industrial and information ages, etc.
An anachronism is something that is "out of place" chronologically.
The golden vase in Time Tangled Island belongs to the Oracle on Greece. I do not know what time period it is, however.
niobium period
The colonial period