In one sentence, describe what the following article is about:

The base drone is the foundation upon which all didj sounds are built. You will keep droning, even as you add other sounds to the mix. Relax your lips and blow through them causing them to vibrate. Some would liken this to "giving a raspberry" or imitating a horse blowing air out of its mouth. This will be similar to, but not exactly, like a brass musician preparing to play. Your lips will need to be a bit looser than a trumpet players. It may be helpful to practice in front of a mirror. When you feel like you can hold your drone for 20 seconds or so, go ahead and put your mouth against the opening of your didgeridoo. Your lips should lay firmly, but not inflexible, against the mouthpiece. They'll need to move without letting any air out. You don't have to directly align your lips with the mouthpiece. Some people prefer to play from the side of their mouth. You can add beeswax to your mouthpiece to make it softer and to create a better seal. Warm up the wax until it is malleable, add it to the rim, and adjust to create an opening hole. Keep in mind that the larger the hole, the more air that is required to play. Most people learning using a 3cm diameter center hole. You can continue to adjust the wax as you play. Once you begin your drone, you can alter the sound by consciously altering the tension in your lips. The sound will also give you feedback. For example, if your lips are too tight then the didj will emit a higher, trumpeting sound. Drop your jaw and move away from a smile to hear a more soothing tone in a lower register. Tap your tongue on your teeth. Quickly push your tongue against the roof of your mouth. Roll your tongue as if you are trying to say an extended "r" in Spanish. Wave your tongue from side to side in your mouth. Allow your cheeks to puff out a bit with extra air. Alternate cheeks for additional sound changes. Be careful to continue your base drone as you make these adjustments. Make all of these movements quickly and methodically. If you linger too long on any one movement, you could possibly kill off your drone by stopping the air flow. Puffing out your cheeks will result in a more even sound whereas tightening them with sharpen it. The diaphragm is a muscle that helps to push air in and out of your lungs. The diaphragm is powerful and can create short bursts of air that will, in turn, create a pulsing sound in your didj. To do this try making a "hahaha" or laughing noise without using your actual voice. You can do this softly or forcefully. Keep a steady drone and then get creative with your tones and sounds. Form your mouth as if you were about to say a letter, such as "A," then keep the drone going and see how that changes the harmonics. Try repeating various vowels combos, like "AOE." This will require that you carefully monitor your breathing. It is also quite common to make animal sounds on the didj. Try a bark for dingo. Or, maybe a more complex "Kuku" noise for the Kukubarra.
Develop and practice your base drone apart from your didj. Place your lips on the didj. Tighten or loosen your lips. Engage your tongue and cheeks. Involve your diaphragm. Experiment with unique vocalizations.