半夜起来唱忐忑

In literal translation this means 'Getting Up in the Middle of Night To Sing Worry Song'. It describes someone who suddenly wakes up from sleep, perhaps because of restlessness or unease and finds themselves compelled to sing out those feelings of worry or angst through music, possibly referring specifically to a song titled “Tanzi”(which roughly means restless or anxious). The implication can be quite vividly humorous and whimsical as it pictures a scene where someone does something peculiar under the spell of midnight restlessness.