This proposal aims to add some types on existing other vocal (which contains only spoken now) will allow to specify the perfomed vocal in AR "artist-recording":

• a cappella ( http://en.wikipedia.org/wiki/A_cappella )
• child's (particularly for choir vocal or performed by [unknown])
• female (particularly for choir vocal or performed by [unknown])
• male (particularly for choir vocal or performed by [unknown])
• mixed (for choir vocal)
• modified (speeded up as in "The Purple People Eater" http://en.wikipedia.org/wiki/The_Purple_People_Eater or in "Witch Doctor" http://en.wikipedia.org/wiki/Witch_Doctor_%28song%29 , slowed down, etc.)
• recitation (of poems or other texts, as distinct from spoken vocal which implies an interview, an announcement, a chatter, etc.)
• scat singing ( http://en.wikipedia.org/wiki/Scat_singing )
• whistling
• whisper
• yodeling ( http://en.wikipedia.org/wiki/Yodelling )