On October 11 and October 25, New York and Chicago will host the annual Hedge Fund Rocktoberfest, raising funds for A Leg To Stand On (ALTSO), a nonprofit organization devoted to offering medical aid to children in developing countries who need prosthetic limbs, corrective surgeries and rehabilitation.

Rockin’ it out: Little Shellah received prosthetics from A Leg To Stand On after losing both legs and being abandoned in an orphanage (left); financial pros by day and musicians by night jam at Hedge Fund Rocktoberfest to raise funds.

As a wildly popular philanthropic event for Wall Street, Rocktoberfest is expanding in its ninth year of existence: Chicago is having its first Rocktoberfest two weeks after New York, and it’s bound to be a success, with corporate sponsorship and an industry-studded audience of over 300 that’s expected to sell out quickly.

The twist, of course, is that Rocktoberfest won’t feature the usual guitarists, drummers, bassists, or singers–every single performer at the fete will be an industry player, rock stars of an entirely different kind: portfolio managers, analysts, lawyers, traders, and the like.

The event is focused on raising funds for and increasing awareness of children in developing countries who, either through unfortunate accident, conflict, or congenital defect, need medical assistance that they otherwise would not be able to get. At an average cost of merely $250 per child, A Leg To Stand On conducts its program of “Training, Treatment, and Therapy” via partnerships with hospitals, other aid organizations and nonprofits and local communities. By encouraging local buy-in and partnerships with nearby organizations, medical communities and recruited physicians, ALTSO achieves its goals by fostering an environment of local self-sufficiency.

Now, with an event in both New York and Chicago, Hedge Fund Rocktoberfest will be raising more than ever for these disadvantaged children. Previous years saw massive success, with otherwise buttoned-up financial types letting loose onstage like pro rockers. Don’t mistake philanthropic volunteerism for amateurism: an application and vetting process is required to play Rocktoberfest–these covert musicians can (and do) rock it out. Chicago will debut its Rocktoberfest at City Winery on West Randolph Street, while New York’s will be at the stunning 583 Park Avenue.

Tickets are currently still available for both NYC and Chicago’s Rocktoberfests ($200 per person until 9/1; $250 after); corporate sponsorships are also available. For further information (including press and sponsorship kits), please visit ALTSO’s official Rocktoberfest website.

Photos courtesy of A Leg To Stand On.