Some 20 odd years ago (yes, I know that they have been indeed odd!) I had a voice student who happened to be a square dance caller, and some of his dance attendees suggested he take voice lessons. The man could not match pitch in any way, shape or form. He had seemingly no ability whatsoever to recognize pitch and produce it. He had to to about 6 other instructors who, upon spending 5-15 minutes with him declined to go on. I agreed that if he were willing to give serious effort, we would leave anything resembling an ego outside the door, & I would work with him. I spent 2-- one hour lessons per week with him. We painstakingly worked on musical concepts such as melody moving up, down, and staying the same. He wandered vocally all up and down the keyboard for several minutes until I would say, "That's it!!" We worked in this such manner, and one day, he really began to be able to hear a pitch, and to my amazement, reproduce it vocally. After about 2 years, he could sing basic melody patterns for square dancing such as "so so so so (octave lower): SOL Ti Do" singing "allemande left and promenade home." When I finished college, I bid him a fond farewell as I left for teaching classroom music somewhere in the midwest. Since this experience, I truly believe that folks who sing "off key" or seemingly "tone deaf" are those who simply have not been taught--or have had a bad experience & are unwilling to sing in front of others. Granted there are some who would need the most extreme devotion on the part of student & instructor, but if we think about all the kids out there who are missing music in the schools, then we will find many kids who come up without having the valuable lessons learned--not just how to sing or play instruments & read music, but the lessons of discipline and wanting something so much that the kid is willing to devote much of their time to the learning. When there are so called "professionals" who sing "off key" it makes me wonder just who hired them & why,-- often with taxpayers money --to sing with professional ensembles & operas!