__________ playing the chords improved our performance.

He
His
Him
He's

His

Thank you! Is there any particular rule that would help with his/him usage?

From Writeacher:

http://guidetogrammar.org/grammar/gerunds.htm#possessive

Because a gerund is basically a noun in the sentence, it needs a possessive in front of it. It wasn’t he who improved the performance; it was his playing the chords that did so.

Thank you so much!

The correct answer is "His playing the chords improved our performance."

To determine the correct answer, we need to understand the subject pronouns and possessive pronouns.

Subject pronouns:
- "He" is used as the subject of a sentence or clause when referring to a male.

Possessive pronouns:
- "His" is a possessive pronoun used to show ownership of something that belongs to a male.

In the given sentence, we are talking about someone playing the chords and how it improved the performance. Here, we need a possessive pronoun to show ownership of the action of playing the chords. Therefore, "His" is the correct pronoun to use.