Is the pitch of growls measurable or is it undefined (for example: bass drum and hi hat are both unpitched but you can tell the relative pitch)? Both me and my friend have good ears and have been unable to tell the pitch that our vocalist is singing when growling, and I haven't found this topic raised anywhere on the internet.
EDIT: Reading a bit on wikipedia about unpitched percussion, I found the term 'inharmonicity' - in simple words it means that the sound produced doesn't interact with the harmony. I would like to know whether growls are harmonic or inharmonic, as it is possible to match pitch with growls but also with drums.
EDIT2: Another bit of information is that our vocalist sings in tune most of the time, with some chance of missing a few notes (when singing clean), but when he growls we can't tell wether he's in tune or not.
EDIT 3: Changed title from "Is growling pitched or unpitched?" to "Do growls interact with the harmony?", meaning, instead of if they have a fundamental pitch (Yes), if they interact with the harmony like clean vocals or don't interact with the harmony like drums (or somewhere in between like pizzicato which is both percussive and melodic).