fair use, copyright, & art
If you're borrowing inspiration from any copyrighted material, even if it seems clear to you that your use is transformational, you're in danger. If your use is commercial and/or potentially objectionable, seek permission (though there's no guarantee it'll be granted) or be prepared to defend yourself in court.
Anyone can file a lawsuit and the costs of defending yourself against a claim are high, regardless of how strong your case is. Combined with vague standards, the result is a chilling effect for every independent artist hoping to build upon or reference copyrighted works.
Andy Baio got musicians together to make a chiptunes tribute to Miles Davis's iconic Kind of Blue. He remade the famous cover to reflect the reformatted music inside: "highly improvisational, warm, and beautiful, from the limited palette of 1980s game consoles." Then he got sued.
His lawyers say it's OK for him to talk now. If you make any kind of art that plays at the boundaries copyright law, you really really need to read this.
(Oh, and if you dig chiptunes or jazz, you really need to hear Kind of Bloop too.)