Well for my two cents worth perfect pitch is split in two parts. If you can properly tune a piano by ear you would have aural perfect pitch but you may not be able to sing in perfect pitch. You may have vocal perfect pitch but not be able to tune that damn piano at all. However if you have a good ear you can train your voice to follow a reference. Most people can come close enough accompanied to annoy only ears that claim perfection. Pitch is only one part of singing, and timing, presentation, and a good song are also just as important!