In the text it says, "She taught me my scales and exercises, too, on the little parlor organ", "I struggled with the 'Harmonious Blacksmith'", and "<span>I had been doggedly beating out some easy passages from an old score of 'Euryanthe'". The boy mostly practiced scales and exercises, but he also played "Harmonius Blacksmith" and "Euryanthe".</span>

I don't recommend using the first person pronoun in an argumentative essay. Unless your instructor suggests that you do so, omit it from the assignment because your writing will read better without it.
The theme of The King’s Magic Drum, is to always be honest. You can be rewarded by telling the truth instead of lying.
Forceful language is language intended to intimidate or forcefully persuade a person with whom you're speaking. It can even include curse words, or can include different intonation elements such as yelling.