Students from Philadelphia attended National Song contest in San Francisco . They prepared six days a week for the competition , where they performed before judges . Philadelphia wants to show city has teens who are doing positive things with lives . `` Most of the people in PYPM do n't have a structured family , but it has n't made them worse people , '' she said . Philadelphia has had problems with flash mobs -- violent attacks on people and property .
Students from Philadelphia attended National Song contest in San Francisco . They prepared six days a week for the competition , where they performed before judges . Philadelphia wants to show city has teens who are doing positive things with lives . Philadelphia has had problems with flash mobs -- violent attacks on people and property .