게 흔들다

shake something like this

흔들다 is shaking something yourself — your head, your body, handlebars — as against 흔들리다, where the thing shakes on its own. The manner word is 이렇게 'like this' in seven of these eight lines, because the speaker is demonstrating: 머리 이렇게 흔들면서 연습하고 있습니다 'I practise shaking my head like this'. It works on feelings too: 로맨스는 우리 마음을 계속 이렇게 흔들어놔요 'romance keeps shaking up our hearts'.

Register: casual