A question was posted as to how to learn to yodel. This is the way I learned. First off, you have to be 'completely' willing to sound awful(like learning the fiddle)at very loud volumes. Yodeling is nothing more than 'clicking' back and forth between your chest and falsetto(head) voices. The problem is most of us smoke or drink our falsetto's away. So, if you smoke it's going to be more difficult, but not impossible. Start out by doing the 'Tarzan yell' as most of us have come to know. This will prep you in the sensation of going back and forth between head/chest voices. Don't worry about maintaining pitch as it's less important at this point than feeling/hearing the 'click' that comes with this skill. Concentrate on the mechanics of 'squeezing ' the back of your throat to obtain the 'head' voice. Once you can do the Tarzan yell pick a note that's comfortable, but in the upper register of your chest voice. Sing the vowel 'Ah'(father). Then 'click' into your head voice holding the same note and vowell, but in a different voice. Don't go up an octave. Stay at the same note. It's different from the Tarzan yell but the process to get the sound is the same. Once you can do this try going back and forth several times in succession. Ok, once that's done then while holding the same note try 'ah then 'ee' while holding your face/mouth in the same position by just raising the back of your tongue(again, you will look/and sound awful, but ya wanna learn or doncha?) Then practice going to intervals within the same chord. For example: if you sing a D(chest) try clicking to an F#(head) and back. Then work your way through the scale to the octave. A good classically trained vocal coach should be able to help you in strengthening your falsetto and pitch problems you will encounter as you learn this technique. Hope this has been helpful. It's exactly the way I started. It's a process and will take time, but it's worth it to learn. Once you can do it and maintain pitch go out and get a bunch of old Slim Whitmen LP's and have at it!