<em><u>Well is an adverb. Well describes how the job was done.</u></em>
In this case, Ivan and Mel are musicians. Good is used in correct context, because they are good at their job. We could not use well in this description because we are not describing how well they did it, we are telling them how good they are at it.
Good is an adjective. In this case, the word good describes the word musicians.<u><em> "They are good musicians."</em></u>
<u>A.</u> The grit is the passion and perseverance before the long-term goals. It is determination, courage, perseverance to achieve success. People with high degree of confidence know what they want, they are insistent and tenacious despite the obstacles that arise. Angela Duckworth associates perseverance with tenacity and willpower.