I too had gotten that bug to tune pianos because I was always just so fascinated by watching my RPT tune my pianos and do minor repairs in the house. Turns out, he teaches apprentices, so I bit. Of course i had to pay him to learn the craft. 3 hours every Saturday. I finally learned how to tune the whole keyboard after about 6 months. The first few were just tuning a few notes and listening to the beats of properly tuned thirds, fourths, fifths and checking the progress with sixths, tenths, thirteenths and so on. I got pretty good at it at close to a year, better after 2 years. In between the tuning lessons were regulations, hammer shaping and parts repair, but we would still after 2 years, set aside one or two lessons per months still dedicated to partials, stability, hammer technique and a lot more. i'm really having fun with this after 5 years and am actually making a few bucks doing tunings and light repairs. I still have a long way to go on the technology end but my customers do like my tunings and call me back. You can learn some basic tuning from a book and videos, but I would recommend learning from a highly experienced RPT if you really want to get good at it. I have two pianos. A Charles Walter that I keep maintained and a Baldwin Spinet that I use for learning purposes. Spinets are more of a PIA to tune than pianos with longer strings and more prominent sounding beats. So far I've regulated it, voiced it, changed the pins and strings (can you believe it? restringing a spinet?) rebushed the flanges, bent damper wires and a host of other regulations and repairs. Like I said, I still have a long way to go. They say you can't tune well until you've tuned 1,000 pianos. I don't know if I'd go that far, but I've done about 700 so far and am still learning. So, give it a whirl. You'll have some frustrating moments and may need your tech to bail you out a few times, but its fun. All the best.