The proprietors of the embattled Gold Dust Lounge are inviting their supporters to a “Sing-A-Long for Willie Brown” on Friday night.

The gathering at the storied Union Square bar is intended to thank the former mayor for his support of the bar, which is facing eviction in March.

In February, Brown submitted supportive testimony to the Historic Preservation Commission, which is considering a request to designate the saloon as a landmark on the grounds that it is “an excellent and representative example of a traditional American cocktail lounge” and “a bastion of the old San Francisco.”

The singalong, which begins at 6 p.m., will feature “Save the Gold Dust Lounge,” an original anthem by singer-songwriter Catherine Hill. The song issues a first-person plea for the Gold Dust, including the line, “I’m not just a bar, I’ve become a home, so get your local supervisor on the phone.”

The song is available for $3 on CD at the bar, or as a 99-cent download at www.golddustloungesf.com.

acrawford@sfexaminer.com