The line in question:
Context: The speaker is monologuing about how terrible society is, especially how corrupt those in power are, he starts to sound nihilistic and basically says he'll act like a criminal because that's what society wants him to act like.
He then mentions the many ways this world could end up being destroyed, by the greed of those in power, by enemies waging war on them etc. But when the world does end he is determined to be a criminal until those final days.
Now back to the question, I don't understand what the speaker means by "心の望むままに情欲を唄おう", translating it literally gives me an odd result "(I/they?) will sing their desires as much as they wish" so I'm thinking there's a more metaphorical meaning behind this that I don't know about yet. I know "心の望むままに" is a set phrase that means "as much as your heart desires" but the 情欲を唄おう is quite confusing. Any help appreciated!