Fears about a City Council bill to regulate concert promoters spilled over from the Internet to City Hall early Thursday afternoon.

A few dozen protesters chanted "Don't repress Philly - express Philly" and "Kill the bill" while holding signs with such messages as "Let freedom sing."

The city's push for the stricter regulations was prompted by police concerns that sometimes, when promoters take over a club, an event can get out of control and authorities can't tell who is in charge.

In January, an outside promoter took over Club Adesso, near 15th and Walnut Streets, and more than 1,200 people filled the place despite a legal occupancy of 149. As more patrons arrived by bus, mayhem ensued, and Walnut Street had to be closed, said Noelle Marconi, legislative director for Councilman Bill Greenlee, one of the bill's proponents.

The concerns at Thursday's rally reflected the views of many, since an online petition to "Throw bill 100267 in the trash" had more than 13,000 signers, and about 4,500 people had joined the "STOP Bill No. 100267" page on Facebook. Those at the rally feared that authorities could force requirements on concert events of all types and sizes - including basement jams and backyard birthday celebrations.

Most of the worries, though, were already being addressed by proposed amendments to the bill, which by Greenlee and Councilman Darrell L. Clarke introduced April 22.

The amendments would drop requirements for concert and party promoters to get permits and sign contracts, according to Marconi.

The promoters would still have to be registered with the city, however, and give written notification to police before taking over a business venue - such as a club, bar, restaurant, or banquet hall - for an event that would draw more than 50 customers.

The bill would not apply to concerts where the venue remained in charge and provided security.

Contact staff writer Peter Mucha at 215-854-4342 or pmucha@phillynews.com.