Before we get down to the nitty gritty of actually learning to growl, you need to listen and learn from some of the great proponents. This was originally one of the many saxophone effects often used as a novelty.
Apart from the fact that it is now one of the main hallmarks of rock and blues saxophone playing, it was also used in mainstream jazz: notably Ben Webster, Illinois Jacquet and Earl Bostic. Charlie Parker also growled on occasions as did avant-garde pioneers John Coltrane and Archie Shepp.
Growl Example 1
In the soundfiles listen to how Ben Webster uses varying degrees of growl, and how Lee Allen uses it on only the first couple of notes to make an opening statement. It is very effective to use any effect in this way and not necessarily as a permanent part of the sound which can lessen its impact.
The first mistake people often make is to think you actually growl (or even roar) into your saxophone. You can try your best lion, dog or badger impressions, but they are unlikely to be as successful as just plain humming while you play, which is generally accepted as the best way to make a saxophone growl.
Ok, so humming a long with what you play seems easy enough, but it’s also a common mistake to think you hum the notes you play, but the pitch of the note you need to harm is not necessarily the same note as you are fingering/playing. We don’t need to get into too much acoustic theory, but very simply the note you sing causes interference with the note you play, and the result is the distorted tone that we call growling.
The ideal note to sing can vary, it could be a harmony note or the same note slightly out of tune. However I’ have not yet found any real rules about whether there is a specific harmony or pitch relative to the saxophone note, so I find the best method is a kind of trial and error which, before you realise it, becomes automatic.
How to practise growling
I find the best way to practice this is to play a clean note, then while holding the note steady, hum any old note in the back of your throat. Alter the pitch of this hummed note until the interference with the saxophone note creates a good growl and hold it there for as long as you can.
Repeat the process with different notes, (if you want to be really disciplined you can go slowly up and down the chromatic scale) doing the same on each note. You will gradually get a feel for which note to sing or hum, and after a while you should be able to do this without thinking about it.
As with any effect, the growl can lose its “effectiveness” if overdone. That isn’t to say there aren’t contexts in which you can usefully use the growl constantly, but these are often kept to short solos in an appropriate genre, e.g. Rock & Roll. It’s useful to be able turn it off and on, or vary the intensity.
Growling as a Part of Your Tone
Ideally you will learn to control your growl to such an extent that you are able to add just a very very slight amount to your sound. You should be able to do this so instead of being heard as an actual growl, what it does is just give your tone a little bit of edge or brightness.