"There is no support for the assertion that Watkins had a First Amendment right to sing any sort of song in the post office lobby while standing in the service line."

That's the conclusion in this 11th Circuit unpublished decision, which starts out:

This case ensued after plaintiff-appellant Eric Watkins was asked to leave a post office and was denied service because he refused to stop singing. Watkins brought suit against defendant-appellee Jackie White, the postal employee who asked Watkins to leave and did not allow Watkins to purchase a post office box after he disregarded her instruction to stop singing. Proceeding pro se, Watkins appeals the district court’s order granting White’s motion to dismiss for failure to state a claim, averring that White violated his right to free speech under the First Amendment to the United States Constitution.
On appeal, Watkins argues that he established a cognizable First Amendment claim because White retaliated against him for his exercise of free speech by ordering him to leave the post office and not permitting him to buy a mailbox while singing. Watkins contends that the lyrics to the song he was singing were “antigay” and that White restricted his speech based on its content. He further avers that White did not have the authority to restrict his speech. However, upon review of the record and consideration of the parties’ briefs, we find that the restriction on Watkins’s speech was reasonable and that White is entitled to qualified immunity. Thus, we affirm the district court’s dismissal of the case.