Iyaz gave an invite-only performance for 250 guests at the Steve Madden store at Ludlow and Rivington Sts. on March 23. Neighborhood kids were outside singing along to the rapper’s beats. Footwear mogul Madden, who climbed to fame on the strength of his clunky-heeled women’s shoes, launched a music division a few years ago. Iyaz — rapping, top, and with fans, above — is a Steve Madden Music artist.