riff

riff とはギターリフのように繰り返される部分でリフレインとも呼ばれている。0:33 I know because I am a comedian. there's no better feeling than when people laugh. it just really makes you feel good. so he just got carried away with it and it went to his head. after that, he just started riffing and..... 私はコメディアンだから人に笑ってもらえば気分がよくなる。法王様も勢いに流されて調子付いてしまって、冗談を次から次へと飛ばし始めた。

Jokes from the Pope
https://www.youtube.com/watch?v=5WICgADzDqw  7:35 created with John Lennon and featuring a memorable guitar riff from Carlos Alomar, ギターリフ

練習問題解答
a-1246 riff
a-2926 a simple riff
a-8306 a long riff on it 注；riff = differences, variation
b-1051 riff
b-3820 riffing on