Context: The second decline was not as complete as the first. Thousands of people had learned to play the instrument. Even as the second wave of mandolin popularity declined in the early 20th century, new versions of the mandolin began to be used in new forms of music. Luthiers created the resonator mandolin, the flatback mandolin, the carved-top or arched-top mandolin, the mandolin-banjo and the electric mandolin. Musicians began playing it in Celtic, Bluegrass, Jazz and Rock-n-Roll styles — and Classical too.

Question: When was the second decline of mandolin popularity?
Answer: early 20th century,

Question: Why was the second decline in popularity not a strong as the first?
Answer: Thousands of people had learned to play the instrument

Question: Who created the rasonator mandolin?
Answer: Luthiers

Question: What are two types of new mandolins the Luthiers created?
Answer: mandolin-banjo and the electric mandolin

Question: What types of music did musicians begin to play the mandolins in?
Answer: Celtic, Bluegrass, Jazz and Rock-n-Roll styles — and Classical too.

Question: When did the first wave of mandolin popularity decline?
Answer: Unanswerable

Question: Who created the resonator mandolin in the early 20th century?
Answer: Unanswerable

Question: What old forms of music was the mandolin used in during the 20th century?
Answer: Unanswerable

Question: When was the second rise of mandolin popularity?
Answer: Unanswerable

Question:  Why was the second rise in popularity not a strong as the first?
Answer: Unanswerable

Question:  Who destroyed the resonator mandolin?
Answer: Unanswerable

Question:  What is the third type of new mandolins the Luthiers created?
Answer: Unanswerable

Question:  What types of music did musicians never play the mandolins in?
Answer: Unanswerable