The singer-actress, who was scheduled to make her 54 Below debut, tweeted, "I have some upsetting news. I had to cancel my @54below show tonight. After fighting a an upper respiratory infection all week, it has now turned into a bad case of bacterial laryngitis. I can't even speak enough to say my own name. The ENT said there is NO way I can sing tonight. I have never had to cancel a show like this!! I truly hope you all can make it to my rescheduled show and maybe even people who COULDN'T Make it, will be able to now! Rescheduled date info to come next week! Stay tuned! Again, my sincere apologies "

The 11 PM concert promised "brand-new arrangements of pop favorites, highlights from her EP and maybe even an interactive 'Breaking Down The Riffs' segment."

Weiss, who is known for her various YouTube performances and her web series "Breaking Down the Riffs," has also been seen in the national tour of Wicked and Season Four of Fox's "American Idol."

Click here for the recent Playbill Playlist from Weiss, who shares her "Riff List." 

54 Below is located at 254 W. 54th Street. For more information visit 54Below.com.