Answer: Situational Irony.
Step-by-step explanation:
There are many literary devices that are used to either, explain, assess, or even simply understand a given situation.
We are tasked in this particular statement to find what the irony is in the following sentence: "A famous singer sings her own song at a karaoke bar but is booed."
In its most simplest form, Irony can be used to describe the unexpected or a particular scenario that is not "the norm".
When we analyze this particular scenario we can recognize that the irony takes root when "the famous singer's" "own song" "is booed".
The introduction of this sentence heavily implies that the famous singer should be able to typically engage and entertain the audience beyond comprehension considering not only their exceptional singing ability but also that they should have a mastery of their own song, but to the reader's surprise, it is quite the opposite.
Thus creating what is known as: Situational Irony.