TASK DEFINITION: Rewrite each original sentence in order to make it easier to understand by non-native speakers of English. You can do so by replacing complex words with simpler synonyms (i.e. paraphrasing), deleting unimportant information (i.e. compression), and/or splitting a long complex sentence into several simpler ones. The final simplified sentences need to be grammatical, fluent, and retain the main ideas of their original counterparts without altering their meanings.
PROBLEM: In popular music, a side project is a project undertaken by one or more persons already known for their involvement in another band.

SOLUTION: In popular music, a side project is a project by one or more people from another band.

PROBLEM: This made her a first cousin of the King's second wife, Anne Boleyn.

SOLUTION: She's the cousin of the King's second wife.

PROBLEM: On August 7, 1953, Congress passed a law retroactively setting the date of Ohio's statehood at March 1, 1803, the date when Ohio's first legislature convened.

SOLUTION:
Congress passed a law to change the date of Ohio's statehood to March 1, 1803.